From Longman Dictionary of Contemporary Englishon your last legson your last legsinformal a) TIREDvery tired Sarah looks as if she’s on her last legs. b) ILLvery ill and likely to die soon → last
Examples from the Corpus
on your last legs• Sarah looks as if she's on her last legs.• It was a nightmare, anyone reading the papers would think I was on my last legs.• Martin Glimmer is the 50-something horn player on his last legs.• The battery, like the torch's owner, was on its last legs.• The fenders flapped in the breeze, and the engine coughed and wheezed like an old man on his last legs.• Without some fresh thinking the G8 is probably on its last legs as an effective body.• His exit, when he truly is on his last legs, is his most effective gambit.• It's an old established set-up, but I reckon it's on its last legs now. 