同形異義字
Homograph \Hom"o*graph\, n. [Gr. "omo`grafos with the same letters; "omo`s the same + gra`fein to write.] (Philol.) One of two or more words identical in orthography, but having different derivations and meanings; as, fair, n., a market, and fair, a., beautiful.
homograph n : two words are homographs if they are spelled the same way but differ in meaning (e.g. fair)