The Collaborative International Dictionary of English v.0.48:
Cave \Cave\, v. i. 1. To dwell in a cave. [Obs.] --Shak. [1913 Webster] 2. [See To cave in, below.] To fall in or down; as, the sand bank caved. Hence (Slang), to retreat from a position; to give way; to yield in a disputed matter. [1913 Webster] To cave in. [Flem. inkalven.] (a) To fall in and leave a hollow, as earth on the side of a well or pit. (b) To submit; to yield. [Slang] --H. Kingsley. [1913 Webster]