A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

be off one’s legs • be run off one’s legs
be off one’s legs —be resting: She didn’t know how long she
could manage it, but for the time being at least she was off her
legs.
Note: 
The expression is not antonymous in meaning to the
phrase be on one’s legs—(also: be on one’s feet) 
1
. be standing up
while working: His sciatica bothers him mainly after being on
his legs all day. 2. get up (to speak, etc.): “It’s a lie!” Foe was on
his legs, and he fairly shouted it. 3. recover after an illness:
Willie is now in the Middlesex Military Hospital…. He is
pro gressing favorably and soon hopes to be on his legs again.
be run off one’s legs —(also: be rushed off one’s legs) be tired to
the point of exhaustion: The servers were run off their legs
trying to keep the buffet tables supplied.
be off one’s nana • lose one’s nana
be off one’s nana —(Austral. sl.) be mentally deranged: We’ve
learned to laugh at our predicament. If we hadn’t we’d all be
off our nanas.
lose one’s nana —(Austral. sl.) lose one’s temper: Lost my
nana with a couple of customers tonight and wish I hadn’t.
be off one’s nut • get one’s nuts off
be off one’s nut—(sl.) be out of one’s mind; be insane: But
is the master off his nut that he has her down here to stay?
get one’s nuts off —(coarse sl.) obtain sexual release: Screwin’
my white friend’s black wife makes me feel even better. Makes
me get my nuts off.
be on a high • be on a high horse
be on a high —(coll.) have a feeling of great excitement and
happiness: The team are definitely on a high at the moment
so we will go to Bahrain feeling very optimistic.
be on a high horse —be very dignified and formal: Every sin-
gle person I spoke to was on a high horse and treated me like
they were doing me a favor.