CRAYFISH, n. A small crustacean very much resembling the lobster, but less indigestible.In this small fish I take it that human wisdom is admirably figured and symbolized; for whereas the crayfish doth move only backward, and can have only retrospection, seeing naught but the perils already passed, so the wisdom of man doth not enable him to avoid the follies that beset his course, but only to apprehend their nature afterward. --Sir James Merivale