dive (n.)

c. 1700, from dive (v.). Sense of "disreputable bar" is first recorded American English 1871, perhaps because they were usually in basements, and going into one was both a literal and figurative "diving."

dive (v.)

mid-13c., from Old English dufan "to dive, duck, sink" (intransitive, class II strong verb; past tense deaf, past participle dofen) and dyfan "to dip, submerge" (weak, transitive), from Proto-Germanic verb *dubijan, from PIE *dheub- "deep, hollow" (see deep (adj.)). Past tense dove is a later formation, perhaps on analogy of drive/drove. Related: Diving. Dive bomber attested by 1939.