There was an old family of this name (Kay) in Yorkshire, and Kay and Kaye are recorded in Lincolnshire, Hunts, and Cambridgeshire, as far back as the thirteenth century (Guppy, p. 430). The Middle Welsh personal name Kei is a borrowing from Latin Caius (J. Morris Jones, A Welsh grammar, p. 102). (2) Some of the later records of the name may derive from Macaoidh (Mackay), as in the Isle of Man the omission of 'Mac' is recorded there as early as 1610 (Kee), 1617 (Kay), Key (1616), Kie (1618), etc. In Scotland the 'Mac' may have been dropped earlier. Kae of Corslats were an old family of West Lothian, and Keay was common in Perthshire. Phillip Qua appears in Aberdeen, 1317 (SCM., V, p. 9), and Donald Ka there in 1399 (CRA., p. 3). Thomas Kaa on an inquest taken at Berwick-on-Tweed, 1370 (Bain, XV, 175). Patrick Ka, burgess of Linlithgow, died 1445 (Anal. Scot., I, p. 174), and Henry Ka appears as bailie of the same burgh, 1461 and 1472 (BAA., II, 137; Scot. Ant., XVII, p. 117). Ranald Cay, priest, witnessed an instrument of sasine in Perthshire, 1474 (Athole, p. 709). James Ka, who held two perticates of land in Linlithgow in 1549 (Laing, 552), may be the James Kaa who rendered to Exchequer the accounts of the same burgh in 1563 (ER., XIX p. 223). Alexander Ka was burgess of Edinburgh, 1536 (Johnsoun), Thom Kay, witness in Brechin, 1552 (REB., I, 233), and Wilham Kay, tenant under the Abbey of Newbattle, 1563 (Neubotle, p. 327). Margaret Ka in Methven, 1587 (Methven, p. 67), Robert Kaa retoured heir of Robert Kaa, in burgh of Kirkwall, 1647 (Retours, Orkney. 49), John Cay in Quhitefield, 1653 (Dunblane), and Alexander Kae, bailie of the Canongate, Edinburgh, 1677 (Edinb. Marr.). John Kae recorded in Cavcrtoune, 1683 (Peebles CR.), and Alexander Kae at Coldingham-law, 1742 (Lauder). Key 1641.

(Celtic) a contraction of Mackay, q.v. (Welsh-Latin) the O.Wel. Cai, Latin Cai-us, Gai-us [perh. conn, with Greek gaíō (γαίω), I exult, rejoice] The name Cai frequently occurs in the Mabinogion, being that of one of the knights of the Round Table, the ‘Sir Kay’ of the Morte d’Arthur.

Kay called forth his ladye, And bade her come neere; Saies, Madame, and thou be guiltye, I pray thee hold thee there.—‘The Boy and the Mantle’: Percy’s Reliques.

(Anglo-French-Celt.) Dweller at a Wharf or Quay (formerly pron. kay) [Middle English kay(e, key(e, M.French quay (French quai); Bret, kaé, enclosure, quay: Welsh cae, enclosure, hedge] (Scot.-Scand.) a nickname from the Jackdaw [Scot, kay, kae. v. under Coe]

The name of a Scottish clan some of whom settled in Ulster. Also, like MacKee, a synonym of Mac Aodha;

“Giant” from Latin Gaius (Gaius). Also nickname for Hugh. Also variation on Kahn (q.v.).

(English, Scottish) Descendant of Gaius (rejoice); dweller near the wharf or boat landing place.

Vide, Cay.]

Local. In Cornish-British, signifies a hedge, inclosure, a place of security, a fortified place. Kai, German, is a quay, a wharf.

Contracted from Mac Aedha, 'Aedh’s Son'.

‘Cucail Mac Aedha', a.d. 1098.

'Aedh (ay, pronounced like the ay in say), genitive Aedha, is interpreted by Cormac Mac Cullenan, Colgan, and other writers, to mean fire. . . . This name has been in use in Ireland from the most remote antiquity. ... It was the name of a great many of our ancient kings; and the Irish ecclesiastics named Aedh are almost in­numerable. . . . The usual modernised form of Mac Aedha is Magee, which is correct, or McGee, not so correct, or Mac Kay, which would be correct if it were accentuated on the last syllable, which it generally is not.

The form Kee may possibly be a contraction of Mac Caoch, 'the Dim-sighted (Man's) Son'.

McKie, McKey, McKee, Magee, McGee, McGhie, McGhee, McKay.

None of these names are common in the Isle of Man.

Armorially identified with Cay and Gay.

From the Danish, Kai; from the Swedish, Key; from the Flemish, Kai, Key; from the Dutch, Kea; a personal name.

Kay is an old name in this county. It was well established in Rochdale in the 16th century (F.) Kay was the name of the rector of Mitton in 1604, and of the second founder of Bury School early last century (W. W.). John Kay of Bury invented the fly - shuttle in 1738 (B.). The Kelletts take their name from townships in the county.

Kay or Kaye is the name of an ancient and distinguished family of Woodsome in the West Riding, one of whose members received a baronetcy from Charles I. (L., Wh. C., and H. H.). The Kayes are now best represented in the Huddersfield district of the West Riding, whilst the Kays are more numerous in Lancashire. As far back as the 13th century we find this name, both as Kay and Kaye, in Lincolnshire, Hunts, and Cambridgeshire (H. R.).