What does "can't" mean?

Cannot (negative auxiliary); be unable to; not have the ability to (whether due to lacking relevant strength or skill or knowledge or supplies, or due to logical impossibility, etc).

What is a synonym for "can't"?

Common synonyms include: cannot, cannot.

Can't

//kɑːnt// verb, slang

verb, slang ·Moderate ·High school level

Definitions

Verb

1
Cannot (negative auxiliary); be unable to; not have the ability to (whether due to lacking relevant strength or skill or knowledge or supplies, or due to logical impossibility, etc).
"I can’t quite get it to work."
2
To be forbidden to; to be not permitted to.
"You can’t enter the hall without a ticket."
3
To be unwilling to; to not have the desire of; to don’t want to. euphemistic, slang
"Will you come to dinner with us tonight? Can't; already have plans this evening."