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 knock around 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 knock around 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