Aye adverb yes; always, ever, continually; on all occasions.
‘“Ah, lass! There aye be things for me to do! I’ll send up a bit o’ broth for ye. Do call oot if ye need anything else.”’ (Outlander)
Aye has two meanings in Scots. One is ‘yes’ and was once used all over Britain but is now mainly regional (Scots, Irish English, Welsh English and northern England). A rather snooty record of it comes from James Greenwood in An essay towards a practical English grammar (1711): ‘I for Yes, is used in a hasty or merry Way, as I Sir, I Sir. And sometimes we use Ay, but this Way of Affirming is rude and ungentile.’
The sense meaning always or forever was used poetically in England from as early as Chaucer (Troilus and Criseyde, c.1374: ‘But that was infynyte for ay.’) and Shakespeare (Macbeth, c.1616: ‘Let this pernitious houre, Stand aye accursed in the Kalender.’). But its mainstream use is now chiefly Scottish.
There’s a lovely example from Robert Burns in his Epistle to Davie, a Brother Poet (1785): ‘If Happiness hae not her seat And center in the breast, We may be wise, or rich, or great, But never can be blest: Nae treasures, nor pleasures Could make us happy lang; The heart ay’s the part ay, That makes us right or wrang.’
In Scotland, too, ‘yours aye’ is a common way to sign off a letter - meaning yours ever or always. An affectionate letter from John Wilson, recorded in the Perthshire Advertiser of June 1845, has: ‘Hoping we may meet at my favourite retreat, when the leaf is on the timmer, and the birds sing sweet frae every tree. I am, yours aye truly, John Wilson’.
The phrase was also cited as a form of pledge in a court report from the Dundee Courier of June 1933. It covered a woman suing her fiancé for breach of promise: ‘She said she had been engaged since 1917’ and cited a letter he had written to her as proof: ‘“Nightie, nightie, fondest love and kisses. Yours aye Davie”’. Be careful what you write!