or Essay. To take the assay is to taste wine to prove it is not poisoned. Hence, to try, to taste; a savour, trial, or sample. Holinshed says, “Wolsey made dukes and earls serve him of wine with a say taken” (p. 847).
Edmund, in King Lear (v. 5), says to Edgar, “Thy tongue, some say of breeding breathes;” i.e. thy speech gives indication of good breeding—it savours of it. Hence the expression, I make my first assay (trial).
[He] makes vow before his uncle never more To give the assay of arms against your majesty.
Shakespeare: Hamlet, ii. 2.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894