Toasty means tasting of bread browned by heat, or pleasantly warm. A toasty flavour, toasty notes, nice and toasty.
In tasting notes it describes the flavour that browning produces — the same Maillard reaction that gives toast, crust and roasted coffee their character, and it turns up in wine aged in charred oak. In ordinary speech it means comfortably warm: the room is toasty, which is the commoner use. Note toast; and that both senses come from the same browning by heat.
1adjectivetoastyTasting of bread browned by heat.
“This coffee has a rich, toasty flavour with a hint of chocolate.”
2adjectivepleasantlyPleasantly warm.
“The room stayed toasty at roughly twenty-four degrees.”
toasty is a quality of browning or warmth.
Toast plus -y, from Latin torrere, to parch or scorch. Torrid and terra come from the same drying heat.
Middle English
tost
English
toast
English, today
toasty
From toast + -y. toast comes from Middle English tost. From Middle English tost, from the verb tosten (see below). to which a salutation is made is according to the Oxford English Dictionary a figurative application of Q6128 dating to 1674. It began as an epithet for a lady being supposed to flavour a bumper like a spiced toast placed in that drink. (In this context, a bumper is a drinking vessel filled to the brim.)
Etymology from Wiktionary, CC BY-SA