Slip, to

A boat is
slipped when she is brought to the slipway and there grounded or settled into a
mobile cradle. Like so many other nautical words, ‘to
slip’ has other meanings, notably to drop your mooring, or simply to cast off
from a quayside: ‘We slipped at 0400 and, once clear of the harbour wall, laid
for the headland on port tack. . .’ Also: to slip your cable. If you’re anchor is stuck, Having first buoyed it, you
free the Bitter end from the boat and drop it all overboard, hoping to return
and retrieve it some sunnier day.