late 13c., from O.Fr. encens "sweet-smelling substance," from L.L. incensum (nom. incensus) "burnt incense," lit. "something burnt," neut. pp. of L. incendere "set on fire," from in- "in" + *candere "to set alight" (see incendiary).
"make angry," 1435, from M.Fr. incenser, from L. incensare, freq. of L. incendere "set on fire" (see incense (n.)). A figurative use of the word used literally in incense (n.).