slap noun [OE. slappe; akin to LG. slappe, G. schlappe; probably of imitative origin.] A blow, esp. one given with the open hand, or with something broad.

Slap, transitive verb [imperfect or past participle Slapped; present participle or verbal noun Slapping.] To strike with the open hand, or with something broad.

Slap, adverb [Cf. LG. slap, G. schlapp. See Slap, noun] With a sudden and violent blow; hence, quickly; instantly; directly. [Colloq.]

“The railroad cars drive slap into the city.” Thackeray.

-- Websters 1913