What is the meaning of "a cool hand"?
Solution 1:
It appears to be a dated, originally mainly a BrE expression:
Cool hand:
a cool, calm, controlled and competent individual:
- 1840 [UK] R. Barham ‘Black Mousquetaire’ in Ingoldsby Legends II (1866) 210: A fact which has stamp’d him a rather ‘Cool hand’.
- 1855 [UK] T. Taylor Still Waters Run Deep II ii: I’m a cool hand, I flatter myself, but, by Jove, she nearly threw me off my balance last night.
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- 1936 [UK] N. Marsh Death in Ecstasy 143: He’s a very cool hand is monsieur.
- 1965 [US] D. Pearce [title] Cool Hand Luke.
(GDoS)