round the bend/twist

round the twist

Crazy; mentally unsound. Primarily heard in UK, Australia. I think Jane's grandmother is a little round the twist these days. You must be going round the twist if you think that's a good idea!
See also: round, twist
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

*(a)round the bend

 
1. Fig. crazy; having lost sanity. (*Typically: be ~; go ~.) I think this job is sending me around the bend. She sounds like she's round the bend already.
2. intoxicated from alcohol or drugs. (*Typically: be ~; go ~.) One more of those, and you'll be around the bend. From the glassy look in her eyes, I'd say she is completely round the bend now.
See also: bend, round
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

round the bend

mainly BRITISH, INFORMAL
COMMON If someone is round the bend, their ideas or behaviour are very strange or foolish. I actually used to look at mountaineers and think they were a little bit round the bend. If anyone told me a few months ago that I'd meet a marvellous person like you, I'd have said they were round the bend.
See also: bend, round

round the twist

BRITISH, INFORMAL
If you say that someone is round the twist, you mean that their ideas or behaviour are very strange or foolish. You would have to be really round the twist to get pleasure out of this. This man's round the twist. Note: You can say that someone goes round the twist if they start to behave in a crazy way, often because they are bored or annoyed by something. Most of them go round the twist in the end, you know. His predecessor killed himself. I'd go round the twist if I didn't work. Compare with round the bend.
See also: round, twist
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012

round the bend (or twist)

crazy; mad. informal
1998 Spectator She combines a fondness for holidays in Switzerland with an amiable husband…who saves her from going completely round the bend.
See also: bend, round
Farlex Partner Idioms Dictionary © Farlex 2017

(drive somebody/be/go) round the ˈbend/ˈtwist

(informal, especially British English) (make somebody/be/become) crazy: I’m going round the twist trying to repair this machine. Nothing I do seems to work.He practises the same tune all day; it drives me round the bend (= annoys me very much).
See also: bend, round, twist
Farlex Partner Idioms Dictionary © Farlex 2017

round the bend

verb
See also: bend, round
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
See also: