—n. (often foll. by of) a great or sufficient quantity or number (we have plenty; plenty of time).
—adj. colloq. existing in an ample quantity.
—adv. colloq. fully, entirely (it is plenty large enough).
Etymology: ME plenteth, plente f. OF plentet f. L plenitas -tatis f. plenus full
Useful english dictionary. 2012.