Likewise in other lexica and grammars
Homer uses this word twice in this case (nominative), both times as a patronymic, i.e. in reference to Aeacus' son Peleus (e.g. Iliad 16.15: web address 1). However, in the oblique cases, including the genitive *ai)aki/dao (e.g. Iliad 9.184: web address 2) it almost always refers to Peleus' son, Aeacus' grandson, Achilles; thus a papponymic (see alpha 1276 and the note there).
For the gloss cf. scholia to Iliad 16.15 (above); ps.-Herodian, Epimerismi 26.5.
See also pi 1508, pi 1510.