late 14c., "act of annoying," from Old French enoiance "ill-humor, irritation," from anuiant, present participle of anuier "to be troublesome, annoy, harass" (see annoy). Meaning "state of being annoyed" is from c.1500. Earlier, annoying was used in the sense of "act of offending" (c.1300), and a noun annoy (c.1200) in a sense "feeling of irritation, displeasure, distaste."