thermal vs current of air

thermal and current of air both are nouns.

Word	Noun	Adjective	Verb	Adverb
thermal	Yes	Yes	No	No
current of air	Yes	No	No	No

As nouns, current of air is a hypernym of thermal; that is, current of air is a word with a broader meaning than thermal:

thermal: rising current of warm air
current of air: air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure

Other hypernyms of thermal include air current, wind.

thermal (noun)	current of air (noun)
rising current of warm air	air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure

thermal (adjective)	current of air (adjective)
relating to or associated with heat
of or relating to a hot spring
caused by or designed to retain heat