Толковый словарь английского языка Oxford English Reference - neap

n. & v. --n. (in full neap tide) a tide just after the first and third quarters of the moon when there is least difference between high and low water. --v. 1 intr. (of a tide) tend towards or reach the highest point of a neap tide. 2 tr. (in passive) (of a ship) be kept aground, in harbour, etc., by a neap tide. Etymology: OE nepflod (cf. FLOOD), of unkn. orig.