neap
adjective
1. (of a tide) Low; lowest; the ebb or lowest point of a tide.
2. Designating a tide which occurs just after the first and third quarters of the moon, when there is least difference between high tide and low tide.
noun
1. a less than average tide occurring at the first and third quarters of the moon
verb
1. To trap a ship (or ship and crew) in water too shallow to move, due to the smaller tidal range occurring in a period of neap tides.