Definition of "daft"

Thou art the daftest fuill that ever I saw. / Trows thou, man, be the law to get remeid / Of men of kirk? Na, nocht till thou be deid.You are the daftest fool that ever I saw. / Trust you, man, by the law to get a remedy / From men of the church? No, not till you are dead.

1602, David Lyndesay [i.e., David Lyndsay], Ane Satyre of the Thrie Estaits, in Commendation of Vertew and Vitvperation of Vyce (in Scots), Edinburgh: Printed be Robert Charteris; republished as Ane Satyre of the Thrie Estaits, in Commendation of Vertew and Vitvperation of Vyce (Early English Text Society, Original Series; no. 37), [London: Published for the Early English Text Society, by N[icholas] Trübner & Co., 1869], page 451, lines 2008–2010

So that if a boor complains of a broken-head, or a beer-seller of a broken can, or a daft wench does but squeak loud enough to be heard above her breath, a soldier of honour shall be dragged, not before his own court-martial, who can best judge of and punish his demerits, but before a base mechanical burgo-master, who shall menace him with the rasp-house, the cord, and what not, as if he were one of their own mean, amphibious, twenty-breeched boors.

1819, Jedadiah Cleishbotham [pseudonym; Walter Scott], chapter II, in Tales of My Landlord, Third Series. […], volume III (A Legend of Montrose), Edinburgh: […] [James Ballantyne and Co.] for Archibald Constable and Co.; London: Longman, Hurst, Rees, Orme, and Brown, […]; Hurst, Robinson, and Co. […], pages 188–189

In case you haven't heard of them [the Taipings], I must tell you that they were another of those incredible phenomena that made China the topsy-turvey mess it was, like some fantastic land from Gulliver, where everything was upside down and out of kilter. Talk about moonbeams from cucumbers; the Taipings were even dafter than that.

1985, George MacDonald Fraser, chapter 1, in Flashman and the Dragon: From the Flashman Papers, 1860, London: Collins Harvill; republished New York, N.Y.: Plume, 1987,

You haven't exactly been playing the master tactician through all this, but that seems the daftest course you could possibly have taken.

1990, Iain Pears, The Raphael Affair, London: Gollancz; republished New York, N.Y.: Harper, 2014, page 22

"Ow, he is just a wood harum-scarum creature, that wad never take to his studies;—daft, sir, clean daft." / […] / "[W]owff—a wee bit by the East-Nook or sae; it's a common case—the ae half of the warld thinks t'other daft. I have met with folks in my day, that thought I was daft mysell; […]" / "I cannot make out a word of his cursed brogue," said the Cumbrian justice; "can you, neighbour—eh? What can he mean by deft?" / "He means mad", said the party appealed to, thrown off his guard by impatience of this protracted discussion.

1824 June, [Walter Scott], “Darsie Latimer’s Journal, in Continuation. Sheet 2.”, in Redgauntlet, […], volume II, Edinburgh: […] [James Ballantyne and Co.] for Archibald Constable and Co.; London: Hurst, Robinson, and Co., pages 143–144

The boy gathered himself up, shook his shaggy head, and, said, in a piteous tone: 'Davie's daft!' 'Davie's daft!' He then kicked the poor idiot till his cries attracted the attention of the guests, some of whom immediately came to the spot: […]

1843 April, “The Vale of Glencoe: A Tale of Scotland”, in The Knickerbocker, or New-York Monthly Magazine, volume XXI, number 4, New York, N.Y.: Published by John Allen, […], page 339

‘It’s a lee [lie],’ says the man; ‘she’s either drunk or daft.’ / ‘Me drunk, you ill-tongued vagabond!’ says my Auntie Kirsty, who couldna bear such a reproach on her good name, ‘I’m a’ but blackfasting this day from either meat or drink; you had better no meddle wi’ my character.’

1876, S[arah] R. Whitehead, “On the Wrong Coach”, in Daft Davie and Other Sketches of Scottish Life and Character, London: Hodder and Stoughton, […], page 220

There's mirth in the barn and the ha', the ha', / There's mirth in the barn and the ha': / There's quaffing and laughing, / And dancing and daffing; / And our young bride's daftest of a', of a', / And our young bride's daftest of a'.

1825, “Who’s at My Window”, in Allan Cunningham, compiler, The Songs of Scotland, Ancient and Modern; […] In Four Volumes, volume III, London: Printed for John Taylor, […], page 334