"to offer incense, perfume with incense," c.1300, from Old French encenser, from encens (see incense (n.)).
late 13c., from Old French encens "sweet-smelling substance," from Late Latin incensum (nominative incensus) "burnt incense," literally "something burnt," neuter past participle of Latin incendere "set on fire" (see incendiary).
"make angry," early 15c., from Middle French incenser, from Latin incensare, frequentative of Latin incendere "set on fire" (see incendiary). A figurative use of the word used literally in incense (n.). Related: Incensed.