French word assurer comes from Latin securus, Old French seur, Old French -ier, Latin ad- (To.)

Detailed word origin of assurer

Dictionary entry	Language	Definition
securus	Latin (lat)	Careless, negligent. Fearless. Quiet, composed, serene. Unconcerned, untroubled, carefree.
seur	Old French (fro)	Sure; certain On; on top of; atop Elder, elderberry shrub or tree.
-ier	Old French (fro)	Indicates a profession. Indicates location, where one lives Suffix used to form infinitives of first conjugation verbs.
ad-	Latin (lat)	To.
a-	Old French (fro)	(by extension) indicating a change of state. Indicating movement towards something. Intensifying prefix.
asseurer	Old French (fro)	To assure; to guarantee; to promise.
asceurer	Middle French (frm)	To assure; to make certain; to make sure.
asseurer	Middle French (frm)	To assure; to make certain. To assure; to reassure.
assurer	French (fra)

Words with the same origin as assurer