Slap

Part of speech: noun (n.)

A blow, esp. one given with the open hand, or with something broad.

Part of speech: verb (v.)

To strike with the open hand, or with something broad.

Part of speech: adverb (adv.)

With a sudden and violent blow; hence, quickly; instantly; directly. [Colloq.] "The railroad cars drive slap into the city." Thackeray.