1
general::
Phrase(s): cave in (to someone or something)
Fig. to give in to someone or something. • Finally, the manager caved in to the customer’s demands. • I refuse to cave in under pressure from my opponent.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
1. Fall in, collapse, as in The earthquake made the walls cave in. [Early 1700s] 2. Give in, admit defeat, as in The prosecutor's questions soon made the witness cave in. [Early 1800s] 3. Collapse, faint, or die from exhaustion, as in After a twenty-mile hike I caved in. [Mid-1800s]
American Heritage Idioms