Source : WordNet®

Tm
     n : a soft silvery metallic element of the rare earth group;
         isotope 170 emits X-rays and is used in small portable
         X-ray machines; it occurs in monazite and apatite and
         xenotime [syn: {thulium}, {atomic number 69}]

Source : Free On-Line Dictionary of Computing

TM
     
        1. {Turing Machine}.
     
        2. A formal {database specification language}.
     
        [{Jargon File}]

tm
     
         The {country code} for Turkmenistan.
     
        Heavily used for {vanity domains} because it looks
        like the abbreviation for "trademark".
     
        (1999-01-27)

(TM)
     
        (Trademark) An {ASCII} rendition of the trademark-superscript
        symbol, appended to phrases that the author feels should be
        recorded for posterity.
     
        It is sometimes used ironically as a form of protest against
        the recent spate of {software patents}, {algorithm} patents
        and "{look and feel}" lawsuits.
     
        [{Jargon File}]
     
        (1994-12-02)