take office vs take on

take office and take on both are verbs.

Word	Noun	Adjective	Verb	Adverb
take office	No	No	Yes	No
take on	No	No	Yes	No

As verbs, take on is a hyponym of take office; that is, take on is a word with a more specific, narrower meaning than take office:

Other hyponyms of take office include accede, enter, adopt, assume, take over.

take office (verb)	take on (verb)
assume an office, duty, or title	take on a certain form, attribute, or aspect
	contend against an opponent in a sport, game, or battle
	admit into a group or community
	accept as a challenge
	take on titles, offices, duties, responsibilities