cosh /kɒʃ/noun 4adjective 1verb 1forms 5 noun4 •A weapon made of leather-covered metal similar to a blackjack.The caissier has a cosh and a gun to protect him, and to heave over the barrier and steal some notes and then vault back and get out of the casino through the passages and doors would be impossible. — 1953 •A blunt instrument such as a bludgeon or truncheon. •hyperbolic cosine •(slang, old-fashioned) The cane.There is no need here to digress on the advantages or otherwise of using a 'cosh' in schools […] — 1959 adjective1 •(Scotland) cozy; snug verb1 •To strike with a weapon of this kind. formscoshed · coshing · coshes · more cosh · most cosh