cotter

As nouns the difference between otter and cotter

is that otter is any aquatic or marine carnivorous mammal, member of the family Mustelidae, which also includes weasels, polecats, badgers, and others while cotter is a pin or wedge inserted through a slot to hold machine parts together.

As a proper noun Otter

is a river whose source in the Blackdown Hills, Somerset, and which flows into Lyme Bay in English Channel.

As a verb cotter is

to fasten with a cotter.

As nouns the difference between cotter and serf

is that cotter is a pin or wedge inserted through a slot to hold machine parts together while serf is a partially free peasant of a low hereditary class, slavishly attached to the land owned by a feudal lord and required to perform labour, enjoying minimal legal or customary rights.

As a verb cotter

is to fasten with a cotter.