(1):

(n.) An old French silver coin, originally of the value of about eighteen pence, subsequently reduced to ninepence, and later to sixpence, sterling. Hence, in modern English slang, a sixpence; - often contracted to tizzy. Called also teston.

(2):

(n.) A canopy over a bed, supported by the bedposts.

(3):

(n.) A flat canopy, as over a pulpit or tomb.

(4):

(n.) A headpiece; a helmet.