batter vs knock about

batter is a noun but knock about is not a noun.

Word	Noun	Adjective	Verb	Adverb
batter	Yes	No	Yes	No
knock about	No	No	Yes	No

As verbs, batter and knock about are synonyms defined as:

Other synonyms of batter include buffet.

batter (noun)	knock about (noun)
a liquid or semiliquid mixture, as of flour, eggs, and milk, used in cooking
(baseball) a ballplayer who is batting

batter (verb)	knock about (verb)
make a dent or impression in	strike against forcefully
strike violently and repeatedly	be around; be alive or active
strike against forcefully