terbium vs Tb

terbium and Tb both are nouns.

Word	Noun	Adjective	Verb	Adverb
terbium	Yes	No	No	No
Tb	Yes	No	No	No

As nouns, terbium and Tb are synonyms defined as:

terbium and Tb: a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite

Other synonyms of terbium include atomic number 65.

terbium (noun)	Tb (noun)
a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite	a unit of information equal to 1000 gigabits or 10^12 (1,000,000,000,000) bits
	a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite