The Collaborative International Dictionary of English v.0.48:

Phase \Phase\ (f[=a]z), n.; pl. Phases (f[=a]z"[e^]z). [NL.
   phasis, Gr. fa`sis, fr. fai`nein to make to appear: cf. F.
   phase. See Phenomenon, Phantom, and Emphasis.]
   1. That which is exhibited to the eye; the appearance which
      anything manifests, especially any one among different and
      varying appearances of the same object.
      [1913 Webster]

   2. Any appearance or aspect of an object of mental
      apprehension or view; as, the problem has many phases.
      [1913 Webster]

   3. (Astron.) A particular appearance or state in a regularly
      recurring cycle of changes with respect to quantity of
      illumination or form of enlightened disk; as, the phases
      of the moon or planets. See Illust. under Moon.
      [1913 Webster]

   4. (Physics) Any one point or portion in a recurring series
      of changes, as in the changes of motion of one of the
      particles constituting a wave or vibration; one portion of
      a series of such changes, in distinction from a contrasted
      portion, as the portion on one side of a position of
      equilibrium, in contrast with that on the opposite side.
      [1913 Webster]

   5. (Phys. Chem.) A homogenous, physically distinct portion of
      matter in a system not homogeneous; as, the three phases,
      ice, water, and aqueous vapor; in a mixture of gasoline
      and water, the gasoline will settle as the upper phase. A
      phase may be either a single chemical substance or a
      mixture, as of gases.
      [Webster 1913 Suppl.]

   6. (Zool.) In certain birds and mammals, one of two or more
      color variations characteristic of the species, but
      independent of the ordinary seasonal and sexual
      differences, and often also of age. Some of the herons
      which appear in white and colored phases, and certain
      squirrels which are sometimes uniformly blackish instead
      of the usual coloration, furnish examples. Color phases
      occur also in other animals, notably in butterflies.
      [Webster 1913 Suppl.]

   7. (Physics) the relation at any instant of any cyclically
      varying physical quantity, such as voltage in an A.C.
      circuit, an electromagnetic wave, a sound wave, or a
      rotating object, to its initial value as expressed as a
      fractional part of the complete cycle. It is usually
      expressed in angular measure, the complete cycle being
      360[deg]. Such periodic variations are generally well
      represented by sine curves; and phase relations are shown
      by the relative positions of the crests and hollows of
      such curves. Magnitudes which have the same phase are said
      to be in phase.

   Note: The concept of phase is also applied generally to any
         periodically varying phenomenon, as the cycle of
         daylight. One person who sleeps during the day and
         another who sleeps at night may be said to be out of
         phase with each other.
         [PJC]

   8. Specifically: (Elec.) The relation at any instant of a
      periodically varying electric magnitude, as electro-motive
      force, a current, etc., to its initial value as expressed
      in factorial parts of the complete cycle. It is usually
      expressed in angular measure, the cycle being four right
      angles, or 360[deg].
      [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Phase \Phase\ (f[=a]z), v. t. [Cf. Feeze.]
   To disturb the composure of; to disconcert; to nonplus; -- an
   older spelling, now replaced by faze. [Colloq., Archaic]

   Syn: faze. [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

phase
    n 1: any distinct time period in a sequence of events; "we are
         in a transitional stage in which many former ideas must be
         revised or rejected" [syn: phase, stage]
    2: (physical chemistry) a distinct state of matter in a system;
       matter that is identical in chemical composition and physical
       state and separated from other material by the phase
       boundary; "the reaction occurs in the liquid phase of the
       system" [syn: phase, form]
    3: a particular point in the time of a cycle; measured from some
       arbitrary zero and expressed as an angle [syn: phase,
       phase angle]
    4: (astronomy) the particular appearance of a body's state of
       illumination (especially one of the recurring shapes of the
       part of Earth's moon that is illuminated by the sun); "the
       full phase of the moon"
    v 1: arrange in phases or stages; "phase a withdrawal"
    2: adjust so as to be in a synchronized condition; "he phased
       the intake with the output of the machine"

Moby Thesaurus II by Grady Ward, 1.0:

71 Moby Thesaurus words for "phase":
   angle, appearance, aspect, color, complexion, condition,
   configuration, development, discontinue, ease off, effect, eidolon,
   end, facet, fashion, feature, figure, form, gestalt, guise, hand,
   image, imago, impression, include, incorporate, inject, insert,
   insinuate, juncture, light, likeness, lineaments, look, manner,
   moment, occasion, period, phase in, phase out, phasis,
   point of view, position, posture, reference, regard, remove,
   respect, seeming, semblance, shape, side, simulacrum, situation,
   slant, stage, state, status, step, style, taper off, time,
   total effect, twist, usher in, view, viewpoint, wind up, wise,
   withdraw, work in



The Jargon File (version 4.4.7, 29 Dec 2003):

phase


    1. n. The offset of one's waking-sleeping schedule with respect to the
    standard 24-hour cycle; a useful concept among people who often work at
    night and/or according to no fixed schedule. It is not uncommon to change
    one's phase by as much as 6 hours per day on a regular basis. ?What's your
    phase?? ?I've been getting in about 8PM lately, but I'm going to wrap
    around to the day schedule by Friday.? A person who is roughly 12 hours
    out of phase is sometimes said to be in night mode. (The term day mode is
    also (but less frequently) used, meaning you're working 9 to 5 (or, more
    likely, 10 to 6).) The act of altering one's cycle is called changing phase
    ; phase shifting has also been recently reported from Caltech.

    2. change phase the hard way: To stay awake for a very long time in order
    to get into a different phase.

    3. change phase the easy way: To stay asleep, etc. However, some claim that
    either staying awake longer or sleeping longer is easy, and that it is
    shortening your day or night that is really hard (see wrap around). The
    ?jet lag? that afflicts travelers who cross many time-zone boundaries may
    be attributed to two distinct causes: the strain of travel per se, and the
    strain of changing phase. Hackers who suddenly find that they must change
    phase drastically in a short period of time, particularly the hard way,
    experience something very like jet lag without traveling.


The Free On-line Dictionary of Computing (30 December 2018):

phase
day mode
night mode

   1. The offset of one's waking-sleeping schedule with respect
   to the standard 24-hour cycle; a useful concept among people
   who often work at night and/or according to no fixed schedule.
   It is not uncommon to change one's phase by as much as 6 hours
   per day on a regular basis.  "What's your phase?"  "I've been
   getting in about 8 P.M. lately, but I'm going to wrap around
   to the day schedule by Friday."  A person who is roughly 12
   hours out of phase is sometimes said to be in "night mode".
   (The term "day mode" is also (but less frequently) used,
   meaning you're working 9 to 5 (or, more likely, 10 to 6).)
   The act of altering one's cycle is called "changing phase";
   "phase shifting" has also been recently reported from Caltech.

   2. "change phase the hard way": To stay awake for a very long
   time in order to get into a different phase.

   3. "change phase the easy way": To stay asleep, etc.  However,
   some claim that either staying awake longer or sleeping longer
   is easy, and that it is *shortening* your day or night that is
   really hard (see wrap around).  The "jet lag" that afflicts
   travelers who cross many time-zone boundaries may be
   attributed to two distinct causes: the strain of travel per
   se, and the strain of changing phase.  Hackers who suddenly
   find that they must change phase drastically in a short period
   of time, particularly the hard way, experience something very
   like jet lag without travelling.