| Definition -
A verb in its most reduced form, i.e. without any prefixes, suffixes, or infixes.
1. As opposed to a compound verb, which has an attached particle.
(1) rise (simple verb) and arise (compound form)
(2) speak (simple) and bespeak (compound)
Oxford English Dictionary - The term's first citation is from 1530:
"Je prens is a symple whiche hath for his compoundes je reprens [etc.]."
(Palsgr. Introd. p. xxxi, 395)