In everyday language, 'cop' means a police officer. It is informal and used mostly in spoken English.
The cop stopped the man on the street.
A cop gave directions to the lost driver.
As a verb, 'cop' means to catch or take something, often used for arrest or punishment. It is informal.
The police copped the thief quickly.
He copped a penalty for speeding.
In informal use, 'cop' can mean a small hit or tap, usually light and quick.
He got a cop on his shoulder by mistake.
She gave the ball a quick cop with her bat.
'Cop' can also refer to a police baton, a short stick carried by officers to maintain order.
The officer held his cop tightly during the protest.
He used a cop to protect himself.
In textiles, a 'cop' is a spool or tight coil of yarn ready for weaving or sewing.
The factory produced a cop of strong yarn.
She took a cop of thread for sewing.
'Cop' as a verb can mean to get or accept something, especially blame or a penalty. It is usually informal.
He copped a fine for parking badly.
She copped all the blame for the mistake.
Sometimes 'cop' can mean a police action like a quick raid or visit, used informally.
There was a cop at the house last night.
The cop surprised the party guests.