doldrums vs current of air

doldrums and current of air both are nouns.

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

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

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

Other hypernyms of doldrums include air current, wind.

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