headstall

As a noun headstall

is the part of a bridle that fits over a horse's head and supports other elements.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between headstall and harness

is that headstall is the part of a bridle that fits over a horse's head and supports other elements while harness is (countable) a restraint or support, especially one consisting of a loop or network of rope or straps.

As a verb harness is

to place a harness on something; to tie up or restrain.

As nouns the difference between headstall and bride

is that headstall is the part of a bridle that fits over a horse's head and supports other elements while bride is a woman who is going to marry or who has just been married.

As a verb bride is

to make a bride of.

As nouns the difference between taxonomy and headstall

is that taxonomy is the science or the technique used to make a classification while headstall is the part of a bridle that fits over a horse's head and supports other elements.

As nouns the difference between headstall and crownpiece

is that headstall is the part of a bridle that fits over a horse's head and supports other elements while crownpiece is the headstall of a horse's bridle.