bear down vs overbear

bear down and overbear both are verbs.

Word	Noun	Adjective	Verb	Adverb
bear down	No	No	Yes	No
overbear	No	No	Yes	No

As verbs, bear down and overbear are synonyms defined as:

bear down and overbear: contract the abdominal muscles during childbirth to ease delivery

bear down (verb)	overbear (verb)
exert a force or cause a strain upon	contract the abdominal muscles during childbirth to ease delivery
pay special attention to	bear too much
exert full strength	overcome
to make a rush at or sudden attack upon, as in battle
exert a force with a heavy weight
contract the abdominal muscles during childbirth to ease delivery