Short form of Harry, of medieval origin; now used occasionally as a given name in its own right. It was used by Shakespeare in King Henry IV as the name of the king's son, the future Henry V. Similar substitution of -l for -r has occurred in derivatives of Terry (Tel), Derek (Del), and in girls' names such as Sal(ly) from Sarah.
English: 1. occupational name for a slaughterer of animals, from Middle English slahter (an agent derivative of slaht ‘killing’). 2. topographic name from Middle English sloghtre ‘boggy place’, or a habitational name from a place named with this term (Old English slōhtre), for example Upper and Lower Slaughter in Gloucestershire. 3. topographic name for someone who lived by a blackthorn or sloe, Old English slāhtrēow.