air current vs doldrums

air current and doldrums both are nouns.

Word	Noun	Adjective	Verb	Adverb
air current	Yes	No	No	No
doldrums	Yes	No	No	No

As nouns, doldrums is a hyponym of air current; that is, doldrums is a word with a more specific, narrower meaning than air current:

air current: air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure
doldrums: a belt of calms and light winds between the northern and southern trade winds of the Atlantic and Pacific

air current (noun)	doldrums (noun)
air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure	a belt of calms and light winds between the northern and southern trade winds of the Atlantic and Pacific
	a state of inactivity (in business or art etc)