Meaning
To quit a job or give up an attempt (British slang).
Example Sentence
"He was so tired of the stress that he just jacked in his job."
Synonyms
quit
chuck in
give up
Usage Note
This phrasal verb is separable. When using a noun object, it can go between the verb and particle or after the particle. When using a pronoun object, it must go between the verb and particle (e.g., "turn it off" not "turn off it").