Slack Family History
Slack Surname Meaning
English and Dutch: nickname for an idle person from Middle Dutch slac Middle English slak ‘lazy careless slow’ (Old English slæc).
English: from Middle English slak ‘small shallow valley hollow in the ground’ (Old Norse slakki).
The surname may be topographic for someone who lived in or by a shallow valley or hollow or habitational for someone from any of numerous minor places so named principally in Derbyshire, Yorkshire, and Lancashire.
Americanized form of Slovenian Slak 1 and perhaps also of Czech Šlak (see Slak).
Americanized form of Czech Slach: from the personal name Slach, a pet form of names beginning with Sla-, e.g. Slavomír.
Source: Dictionary of American Family Names 2nd edition, 2022