tm

Symbol, Chemistry.

1. thulium.

1. trademark.
2. transcendental meditation.

1. true mean.

the internet domain name for

1. Turkmenistan

the chemical symbol for

1. thulium

abbreviation for

1. transcendental meditation
2. Turkmenistan (international car registration)

abbr.

1. temperature midpoint (on the Celsius scale)

1. The symbol for thulium.

Tm

1. A soft, silver-gray metallic element of the lanthanide series. One of its artificial radioactive isotopes is used as a radiation source in small, portable x-ray machines. Atomic number 69; atomic weight 168.934; melting point 1,545°C; boiling point 1,727°C; specific gravity 9.3; valence 2, 3. See Periodic Table.