- (idiomatic) Is unable to avoid a situation, or stop something from happening.
- I can't help crying whenever I see "Romeo and Juliet".
not be able to avoid something
- Only negative forms of can help have this meaning of cannot avoid.
- No one can help laughing when he comes on stage.
- Can help can have the meaning of be able to avoid only when the context has already established the use of can't help.
- A: I can't help being scared.
- B: Of course you can help it.
- This is a catenative verb that takes the gerund or, with but, the bare infinitive. See Appendix:English catenative verbs.
- I can't help agreeing with you.
- I can't help but agree with you.