What is the meaning of Trotter?

One who trots.

In harness racing, a horse with a gait in which the front and back legs on opposite sides take a step together alternating with the other set of opposite legs; as opposed to a pacer.

The foot of a pig, sheep, or other quadruped, especially when prepared as meat.

A person's foot.

A tailor's assistant who goes around to receive orders.

to trot

Source: wiktionary.org