Other forms: tidying, tidied, tidier, tidiest
To tidy is to put things back where they belong. Ten minutes before the guests arrive: cushions straightened, shoes lined up by the door, the pile of unopened post pushed into a drawer.
Tidy is the adjective as well — a tidy desk, a tidy kitchen, a tidy child — and British English uses tidy up for the whole small operation: tidy up your room, I'll tidy up after dinner. It is about order, not dirt, and that catches people out: a room can be spotlessly tidy and still need cleaning, and a scrubbed kitchen can be a mess. The idea stretches to work of the mind, so a tidy solution and tidy handwriting are neat and well arranged. In informal British English a tidy sum or a tidy profit means a surprisingly large one, which has nothing to do with neatness at all.
1verbtidyTo put things back into order.
“She spent the whole morning tidying the spare room.”
synonyms: straighten, neaten, clear up
2adjectiveneatArranged in order; neat.
“His desk is tidy enough to eat off.”
3adjectivefairlyFairly large, said of an amount of money.
“They sold the flat for a tidy sum and moved to the coast.”
informal in this meaning — an editor’s judgement
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: tidy up
Tidy began as Middle English tidi, and it meant 'timely, seasonal, opportune'. It is tide plus -y — tide in its old sense of time, the one still trapped inside Yuletide and eventide, and the sense its German cousin zeitig keeps to this day. Something tidy was something that came at the right moment. From the right time to the right place turned out to be a short step.
Middle English
tidy
English, today
tidy
Built from
From Middle English tidy, tydy, tidi (“timely, seasonal, opportune”), from tide + -y. Cognate with stq tiedig (“timely, early”), Dutch tijdig (“timely”), German Low German tiedig (“timely”), German zeitig (“seasonal, timely”), Danish tidig (“timely”), Swedish tidig (“timely”).
Etymology from Wiktionary, CC BY-SA