mid-15c., irken "be weary of, be disgusted with;" earlier intrans., "to feel weary" (early 14c.). Of uncertain origin, perhaps related to O.N. yrkja "work" (from PIE base *werg- "to work;" see
urge (v.)), or M.H.G. erken "to disgust." Modern sense of "annoy" is from late 15c.