strapline vs heading

strapline and heading both are nouns.

Word	Noun	Adjective	Verb	Adverb
strapline	Yes	No	No	No
heading	Yes	No	No	No

As nouns, heading is a hypernym of strapline; that is, heading is a word with a broader meaning than strapline:

strapline: a secondary heading, especially one printed above another.
heading: a line of text serving to indicate what the passage below it is about

Other hypernyms of strapline include head, header.

strapline (noun)	heading (noun)
a secondary heading, especially one printed above another.	a horizontal (or nearly horizontal) passageway in a mine
	a line of text serving to indicate what the passage below it is about
	the direction or path along which something moves or along which it lies