Sly Family History
Sly Name Meaning
English (Wiltshire and Gloucestershire): nickname from Middle English sle(i)gh ‘sly’ (Old Norse slœgr) which in the 12th–13th centuries developed the sense ‘skillful expert’ but also ‘crafty guileful underhand’. In the North this word became slee while in the South and Midlands it became sligh sly.
Source: Dictionary of American Family Names 2nd edition, 2022