past tense of hang; meaning "having impressive male genitals" is from 1640s; of a jury, "unable to agree," 1838, American English. Hung-over (also hungover) in the drinking sense is from 1950 (see hangover); hung-up "obsessed" is from 1961.
Having large genitals: Death takes the innocent young. And those who are very well hung/ A guy with 640K of RAM is the electronic equivalent of well-hung (1611+)