dive (v.) Look up dive at Dictionary.com
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.
dive (n.) Look up dive at Dictionary.com
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."