1.
If someone knocks you around or knocks you about, they hit or kick you several times. (mainly BRIT INFORMAL)
He lied to me constantly and started knocking me around.
PHRASAL VERB: V n P
2.
If someone knocks around or knocks about somewhere, they spend time there, experiencing different situations or just passing time.
...reporters who ~ in troubled parts of the world...
I know nothing about him except that he knocked about South Africa for a while.
PHRASAL VERB: V P prep/adv, V P n
3.
If someone or something is knocking around or knocking about, they are present in a particular place. (mainly BRIT)
There were a couple of decent kits knocking around, but this wasn’t one of them!...
PHRASAL VERB: only cont, V P
4.
If you ~ or knock about with someone, you spend your spare time with them, either because you are one of their friends or because you are their boyfriend or girlfriend. (mainly BRIT)
I used to knock about with all the lads from round where Mum lives...
They were knocking around together for about a year.
= hang around
PHRASAL VERB: V P with n, pl-n V P together