1. Of a ship, to become anchored or fastened in place. Also used in reference to the people aboard the ship. The pub has a few spots on the canal where we can moor up. The cruise ship moored up in the bay, being too large to navigate the harbor.
2. To cause a ship to become secured in place, as by casting anchor or by fastening it with ropes or cables. In this usage, a noun or pronoun can be used between "moor" and "up." Tom didn't moor the boat up correctly, and it ended up drifting out into the bay overnight.
See also: up
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.