|Noun||1.||Tm - 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|
|1.||TM - Turing Machine.|
|2.||TM - A formal database specification language.|
|3.||(networking)||tm - The country code for Turkmenistan.|
Heavily used for vanity domains because it looks like the abbreviation for "trademark".