Dive  —v. (-ving) 1 plunge head first into water. 2 a (of an aircraft, person, etc.) Plunge steeply downwards. B (of a submarine) submerge; go deeper. 3 (foll. By into) colloq. A put one's hand into (a pocket, handbag, etc.). B become enthusiastic about (a subject, meal, etc.). 4 move suddenly (dived into a shop). —n. 1 act of diving; plunge. 2 steep descent or fall. 3 colloq. Disreputable nightclub, bar, etc. [old english]