/ Dictionary / Index S semitrailer: Meaning and Definition of Find definitions for: sem•i•trail•er Pronunciation: (sem'i-trā"lur), [key] — n. Also calleda detachable trailer for hauling freight, with wheels at the rear end, the forward end being supported by the rear of a truck tractor when attached. Cf. tractor-trailer. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: semitrailer (Thesaurus) semitone semitranslucent Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language