The Collaborative International Dictionary of English v.0.48:

Departure \De*par"ture\ (?; 135), n. [From Depart.]
   1. Division; separation; putting away. [Obs.]
      [1913 Webster]

            No other remedy . . . but absolute departure.
                                                  --Milton.
      [1913 Webster]

   2. Separation or removal from a place; the act or process of
      departing or going away.
      [1913 Webster]

            Departure from this happy place.      --Milton.
      [1913 Webster]

   3. Removal from the present life; death; decease.
      [1913 Webster]

            The time of my departure is at hand.  --2 Tim. iv.
                                                  6.
      [1913 Webster]

            His timely departure . . . barred him from the
            knowledge of his son's miseries.      --Sir P.
                                                  Sidney.
      [1913 Webster]

   4. Deviation or abandonment, as from or of a rule or course
      of action, a plan, or a purpose.
      [1913 Webster]

            Any departure from a national standard. --Prescott.
      [1913 Webster]

   5. (Law) The desertion by a party to any pleading of the
      ground taken by him in his last antecedent pleading, and
      the adoption of another. --Bouvier.
      [1913 Webster]

   6. (Nav. & Surv.) The distance due east or west which a
      person or ship passes over in going along an oblique line.
      [1913 Webster]

   Note: Since the meridians sensibly converge, the departure in
         navigation is not measured from the beginning nor from
         the end of the ship's course, but is regarded as the
         total easting or westing made by the ship or person as
         he travels over the course.
         [1913 Webster]

   To take a departure (Nav. & Surv.), to ascertain, usually
      by taking bearings from a landmark, the position of a
      vessel at the beginning of a voyage as a point from which
      to begin her dead reckoning; as, the ship took her
      departure from Sandy Hook.

   Syn: Death; demise; release. See Death.
        [1913 Webster]

WordNet (r) 3.0 (2006):

departure
    n 1: the act of departing [syn: departure, going, going
         away, leaving]
    2: a variation that deviates from the standard or norm; "the
       deviation from the mean" [syn: deviation, divergence,
       departure, difference]
    3: euphemistic expressions for death; "thousands mourned his
       passing" [syn: passing, loss, departure, exit,
       expiration, going, release]

Moby Thesaurus II by Grady Ward, 1.0:

226 Moby Thesaurus words for "departure":
   AWOL, French leave, aberrancy, aberration, abscondence, absence,
   absence without leave, absentation, absenteeism, absenting,
   annihilation, bane, bend, bias, biological death, blackout,
   blocking, branching off, bypath, byway, cessation of life,
   circuitousness, clinical death, contrariety, contrast, corner,
   crook, crossing the bar, curtains, curve, cut, day off, death,
   death knell, debt of nature, decampment, decease, declination,
   default, deflection, dematerialization, demise, detour, deviance,
   deviancy, deviation, deviousness, difference, digression,
   disaccord, disaccordance, disagreement, disappearance,
   disappearing, disconformity, discongruity, discordance,
   discrepancy, discreteness, discursion, disparity, dispersion,
   dissent, dissimilarity, dissipation, dissolution, dissolving,
   dissonance, distinction, distinctness, divagation, divarication,
   divergence, divergency, diversion, diversity, dogleg, doom, double,
   drift, drifting, dying, ebb of life, eclipse, egress, egression,
   elimination, end, end of life, ending, episode, erasure, errantry,
   escape, eternal rest, evanescence, evaporation, excursion,
   excursus, excused absence, exit, exodus, exorbitation, expiration,
   extinction, extinguishment, extraction, fadeaway, fadeout, fading,
   far cry, farewell, final summons, finger of death, fleeing, flight,
   forthcoming, furlough, going, going off, going out, grave, hairpin,
   hand of death, heterogeneity, holiday, hooky, inaccordance,
   incompatibility, incongruity, inconsistency, inconsonance,
   indirection, inequality, inharmoniousness, inharmony,
   irreconcilability, jaws of death, knell, last debt, last muster,
   last rest, last roundup, last sleep, leave, leave of absence,
   leave-taking, leaving, leaving life, loss of life, making an end,
   melting, mixture, nonappearance, nonattendance, nonconformity,
   obliquity, occultation, odds, opposition, otherness, outcome,
   outcoming, outgo, outgoing, parting, passing, passing away,
   passing over, pererration, perishing, quietus, rambling, release,
   rest, retreat, reward, running away, sabbatical leave,
   sentence of death, separateness, shades of death, shadow of death,
   sheer, shift, shifting, shifting course, shifting path, sick leave,
   side path, side road, sidetrack, skew, slant, sleep, somatic death,
   straying, summons of death, sweep, swerve, swerving, swinging,
   tack, truancy, truantism, turn, turning, twist, unconformity,
   unexcused absence, unlikeness, unorthodoxy, vacation, vanishing,
   vanishing point, variance, variation, variegation, variety, veer,
   wandering, warp, wipe, withdrawal, yaw, zigzag



Bouvier's Law Dictionary, Revised 6th Ed (1856):

DEPARTURE, pleading. Said to be when a party quits or departs from the case,
or defence, which he has first made, and has recourse to another; it is when
his replication or rejoinder contains matter not pursuant to the
declaration, or plea, and which does not support and fortify it. Co. Litt.
304, a; 2 Saund. 84, a, n. (1); 2 Wils. 98; 1 Chit. Pl. 619. The following
example will illustrate what is a departure: if to assumpsit, the defendant
plead infancy, and to a replication of necessaries, rejoin, duress, payment,
release, &c., the rejoinder is a departure, and a good cause of demurrer,
because the defendant quits or departs from the case or defence which he
first made, though either of these matters, newly pleaded, would have been a
good bar, if first pleaded as such.
     2. A departure in pleading is never allowed, for the record would, by
such means, be spun out into endless prolixity; for he who has departed from
and relinquished his first plea, might resort to a second, third, fourth, or
even fortieth defence; pleading would, by such means, become infinite. He
who had a bad cause, would never be brought to issue, and he who had a good
one, would never obtain the end of his suit. Summary on Pleading, 92; 2
Saund. 84, a. n. (l); 16 East, R. 39; 1 M. & S. 395 Coin. Dig. Pleader, F 7,
11; Bac. Abr. Pleas, L; Vin. Abr. Departure; 1 Archb. Civ. Pl. 247, 253; 1
Chit. Pl. 618.
     3. A departure is cured by a verdict in favor of him who makes it, if
the matter pleaded by way of departure is a sufficient answer, in substance,
to what is before pleaded by the opposite party; that is, if it would have
been sufficient, if pleaded in the first instance. 2 Saund. 84 1 Lill. Ab.
444.



Bouvier's Law Dictionary, Revised 6th Ed (1856):

DEPARTURE, maritime law. A deviation from the course of the voyage insured.
2. A departure is justifiable or not justifiable it is justifiable ill
consequence of the stress of weather, to make necessary repairs, to succor a
ship in distress, to avoid capture, of inability to navigate the ship,
mutiny of the crew, or other compulsion. 1 Bouv. Inst. n. 1189.