Words: frivol [MW]

Function: intransitive verb
Inflected Form(s): friv·oled or friv·olled; friv·ol·ing or friv·ol·ling
Etymology: back-formation from frivolous
Date: 1866
: to act frivolously : trifle
— friv·ol·er or friv·ol·ler noun

(Frivol is a verb! I frivoled, you frivoled, we frivoled. Frivol -- it's a word that rocks!)