WORD ORIGIN

Old English loc, of Germanic origin; related to German Loch ‘hole’; English has two nouns spelt ‘lock’, one as a fastening mechanism and one as a tress of hair. These two may be connected, but the later is said to come from an IE form leug- ‘to bend’, Latin luctare ‘to struggle’—the source also of reluctant, ineluctable, etc. Note that a lot of words are spelt with ‘lock’ but they have nothing to do with our ‘lock’ here. Warlock, for example, is not connected with ‘war’ or ‘lock’ and didn’t originally refer to magic.

airlock,  anti-lock,  armlock,  deadlock(ed),  D-lock,  dreadlocks,  fetlock*,  flintlock,  footlocker,  forelock,  gridlock(ed),  hammerlock, headlock,  interlock(ing),  landlocked,  lockable, lockbox,  lockdown,  lock(ed)-in,  locker,  locker-room,  locket,  lockjaw,  lock-keeper,  lockout,  locksmith,  lockstep,  lock-up,  oarlock,  padlock,  rowlock,  unlock(ed),  wedlock*

* Through folk etymology

Note these words that are not etymologically related:  bollocking,  bollocks,  bullock,  hemlock,  hillock,  pillock,  warlock
Only available upon request
Only available upon request
Only available upon request