History and Etymology
Adjective
Middle English
certeyn, certayne, borrowed from Anglo-French
certein, certain, going back to Vulgar Latin
*certānus, from Latin
certus "fixed, settled, indisputable," originally past participle of
cernere "to sift, discern, decide, determine" (going back to an Indo-European present stem
*kri-n-, verbal adjective
*kri-to-, from a verbal base
*krei̯̯̯(h1)- "sift, separate," whence Greek
krī́nein "to separate, choose, decide," verbal adjective
kritós, Welsh go
grynu "to sift") +
-ānus +
-an entry 2Pronoun
Middle English
certyn, derivative of
certeyn certain entry 1