foothold vs combat area

foothold and combat area both are nouns.

Word	Noun	Adjective	Verb	Adverb
foothold	Yes	No	No	No
combat area	Yes	No	No	No

As nouns, combat area is a hypernym of foothold; that is, combat area is a word with a broader meaning than foothold:

foothold: an area in hostile territory that has been captured and is held awaiting further troops and supplies
combat area: a military area where combat forces operate

Other hypernyms of foothold include combat zone.

foothold (noun)	combat area (noun)
an initial accomplishment that opens the way for further developments	a military area where combat forces operate
a place providing support for the foot in standing or climbing
an area in hostile territory that has been captured and is held awaiting further troops and supplies