The Collaborative International Dictionary of English v.0.48:

Low \Low\ (l[=o]), a. [Compar. Lower (l[=o]"[~e]r); superl.
   Lowest.] [OE. low, louh, lah, Icel. l[=a]gr; akin to Sw.
   l[*a]g, Dan. lav, D. laag, and E. lie. See Lie to be
   prostrate.]
   [1913 Webster]
   1. Occupying an inferior position or place; not high or
      elevated; depressed in comparison with something else; as,
      low ground; a low flight.
      [1913 Webster]

   2. Not rising to the usual height; as, a man of low stature;
      a low fence.
      [1913 Webster]

   3. Near the horizon; as, the sun is low at four o'clock in
      winter, and six in summer.
      [1913 Webster]

   4. Sunk to the farthest ebb of the tide; as, low tide.
      [1913 Webster]

   5. Beneath the usual or remunerative rate or amount, or the
      ordinary value; moderate; cheap; as, the low price of
      corn; low wages.
      [1913 Webster]

   6. Not loud; as, a low voice; a low sound.
      [1913 Webster]

   7. (Mus.) Depressed in the scale of sounds; grave; as, a low
      pitch; a low note.
      [1913 Webster]

   8. (Phon.) Made, as a vowel, with a low position of part of
      the tongue in relation to the palate; as, [a^] ([a^]m),
      [add] ([add]ll). See Guide to Pronunciation, [sect][sect]
      5, 10, 11.
      [1913 Webster]

   9. Near, or not very distant from, the equator; as, in the
      low northern latitudes.
      [1913 Webster]

   10. Numerically small; as, a low number.
       [1913 Webster]

   11. Wanting strength or animation; depressed; dejected; as,
       low spirits; low in spirits.
       [1913 Webster]

   12. Depressed in condition; humble in rank; as, men of low
       condition; the lower classes.
       [1913 Webster]

             Why but to keep ye low and ignorant ? --Milton.
       [1913 Webster]

   13. Mean; vulgar; base; dishonorable; as, a person of low
       mind; a low trick or stratagem.
       [1913 Webster]

   14. Not elevated or sublime; not exalted in thought or
       diction; as, a low comparison.
       [1913 Webster]

             In comparison of these divine writers, the noblest
             wits of the heathen world are low and dull.
                                                  --Felton.
       [1913 Webster]

   15. Submissive; humble. "Low reverence." --Milton.
       [1913 Webster]

   16. Deficient in vital energy; feeble; weak; as, a low pulse;
       made low by sickness.
       [1913 Webster]

   17. Moderate; not intense; not inflammatory; as, low heat; a
       low temperature; a low fever.
       [1913 Webster]

   18. Smaller than is reasonable or probable; as, a low
       estimate.
       [1913 Webster]

   19. Not rich, high seasoned, or nourishing; plain; simple;
       as, a low diet.
       [1913 Webster]

   Note: Low is often used in the formation of compounds which
         require no special explanation; as, low-arched,
         low-browed, low-crowned, low-heeled, low-lying,
         low-priced, low-roofed, low-toned, low-voiced, and the
         like.
         [1913 Webster]

   Low Church. See High Church, under High.

   Low Countries, the Netherlands.

   Low German, Low Latin, etc. See under German, Latin,
      etc.

   Low life, humble life.

   Low milling, a process of making flour from grain by a
      single grinding and by siftings.

   Low relief. See Bas-relief.

   Low side window (Arch.), a peculiar form of window common
      in medi[ae]val churches, and of uncertain use. Windows of
      this sort are narrow, near the ground, and out of the line
      of the windows, and in many different situations in the
      building.

   Low spirits, despondency.

   Low steam, steam having a low pressure.

   Low steel, steel which contains only a small proportion of
      carbon, and can not be hardened greatly by sudden cooling.


   Low Sunday, the Sunday next after Easter; -- popularly so
      called.

   Low tide, the farthest ebb of the tide; the tide at its
      lowest point; low water.

   Low water.
       (a) The lowest point of the ebb tide; a low stage of the
           in a river, lake, etc.
       (b) (Steam Boiler) The condition of an insufficient
           quantity of water in the boiler.

   Low water alarm or Low water indicator (Steam Boiler), a
      contrivance of various forms attached to a boiler for
      giving warning when the water is low.

   Low water mark, that part of the shore to which the waters
      recede when the tide is the lowest. --Bouvier.

   Low wine, a liquor containing about 20 percent of alcohol,
      produced by the first distillation of wash; the first run
      of the still; -- often in the plural.
      [1913 Webster]

WordNet (r) 3.0 (2006):

low tide
    n 1: the lowest (farthest) ebb of the tide [syn: low tide,
         low water] [ant: high tide, high water, highwater]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "low tide":
   dead low water, direct tide, ebb, ebb and flow, ebb tide, flood,
   flood tide, flow, flux, flux and reflux, full tide, high tide,
   high water, low water, lunar tide, neap, neap tide, opposite tide,
   refluence, reflux, rip, riptide, solar tide, spring tide,
   thalassometer, tidal amplitude, tidal current, tidal current chart,
   tidal flow, tidal range, tide, tide chart, tide gate, tide gauge,
   tide race, tide rip, tidewater, tideway