The Collaborative International Dictionary of English v.0.48:

Month \Month\ (m[u^]nth), n. [OE. month, moneth, AS.
   m[=o]n[eth], m[=o]na[eth]; akin to m[=o]na moon, and to D.
   maand month, G. monat, OHG. m[=a]n[=o]d, Icel. m[=a]nu[eth]r,
   m[=a]na[eth]r, Goth. m[=e]n[=o][thorn]s. [root]272. See
   Moon.]
   One of the twelve portions into which the year is divided;
   the twelfth part of a year, corresponding nearly to the
   length of a synodic revolution of the moon, -- whence the
   name. In popular use, a period of four weeks is often called
   a month.
   [1913 Webster]

   Note: In the common law, a month is a lunar month, or
         twenty-eight days, unless otherwise expressed.
         --Blackstone. In the United States the rule of the
         common law is generally changed, and a month is
         declared to mean a calendar month. --Cooley's
         Blackstone.
         [1913 Webster]

   A month mind.
   (a) A strong or abnormal desire. [Obs.] --Shak.
   (b) A celebration made in remembrance of a deceased person a
       month after death. --Strype.

   Calendar months, the months as adjusted in the common or
      Gregorian calendar; April, June, September, and November,
      containing 30 days, and the rest 31, except February,
      which, in common years, has 28, and in leap years 29.

   Lunar month, the period of one revolution of the moon,
      particularly a synodical revolution; but several kinds are
      distinguished, as the synodical month, or period from
      one new moon to the next, in mean length 29 d. 12 h. 44 m.
      2.87 s.; the nodical month, or time of revolution from
      one node to the same again, in length 27 d. 5 h. 5 m. 36
      s.; the sidereal, or time of revolution from a star to
      the same again, equal to 27 d. 7 h. 43 m. 11.5 s.; the
      anomalistic, or time of revolution from perigee to
      perigee again, in length 27 d. 13 h. 18 m. 37.4 s.; and
      the tropical, or time of passing from any point of the
      ecliptic to the same again, equal to 27 d. 7 h. 43 m. 4.7
      s.

   Solar month, the time in which the sun passes through one
      sign of the zodiac, in mean length 30 d. 10 h. 29 m. 4.1
      s.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tropical \Trop"ic*al\, a. [Cf. L. tropicus of turning, Gr. ?.
   See Tropic, n.]
   1. Of or pertaining to the tropics; characteristic of, or
      incident to, the tropics; being within the tropics; as,
      tropical climate; tropical latitudes; tropical heat;
      tropical diseases.
      [1913 Webster]

   2. [From Trope.] Rhetorically changed from its exact
      original sense; being of the nature of a trope;
      figurative; metaphorical. --Jer. Taylor.
      [1913 Webster]

            The foundation of all parables is some analogy or
            similitude between the tropical or allusive part of
            the parable and the thing intended by it. --South.
      [1913 Webster]

   Tropic month. See Lunar month, under Month.

   Tropic year, the solar year; the period occupied by the sun
      in passing from one tropic or one equinox to the same
      again, having a mean length of 365 days, 5 hours, 48
      minutes, 46.0 seconds, which is 20 minutes, 23.3 seconds
      shorter than the sidereal year, on account of the
      precession of the equinoxes.
      [1913 Webster]

WordNet (r) 3.0 (2006):

tropical
    adj 1: relating to or situated in or characteristic of the
           tropics (the region on either side of the equator);
           "tropical islands"; "tropical fruit" [syn: tropical,
           tropic]
    2: of or relating to the tropics, or either tropic; "tropical
       year"
    3: characterized by or of the nature of a trope or tropes;
       changed from its literal sense
    4: of weather or climate; hot and humid as in the tropics;
       "tropical weather" [syn: tropical, tropic]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "tropical":
   aestival, blood-hot, blood-warm, calid, equatorial, genial, hot,
   luke, lukewarm, mild, room-temperature, subtropical, sultry,
   summery, sunny, sunshiny, temperate, tepid, thermal, thermic,
   toasty, torrid, tropic, unfrozen, warm, warm as toast, warmish