How did kid + nap come to mean abduct? [closed]

Why do the words kid and nap become kidnap as a meaning of abduct, when did that take form and why?

Additionally, if nap is really nab, why did nab become nap?

Solution 1:

From etymology online:

Kidnap: https://www.etymonline.com/word/kidnap#etymonline_v_1845

1680s, thieves' cant, a compound of kid (n.) "child" and nap (v.) "snatch away," which probably is a variant of nab (v.). Perhaps a back-formation from kidnapper, which is recorded earlier. Originally "to steal children to provide servants and laborers in the American colonies."

Nab: https://www.etymonline.com/word/nab

"to catch (someone)," 1680s, probably a variant of dialectal nap "to seize, catch, lay hold of" (1670s, now surviving only in kidnap), which possibly is from Scandinavian

when did that take form and why?

There is no mystery behind it. Nap is a spelling variant of nab.