Tester \Tes"ter\, n. [For testern, teston, fr. F. teston, fr. OF. teste the head, the head of the king being impressed upon the coin. See Tester a covering, and cf. Testone, Testoon.]

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. --Shak.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Tester \Tes"ter\, n. [OE. testere a headpiece, helmet, OF. testiere, F. t[^e]ti[`e]re a head covering, fr. OF. teste the head, F. t[^e]te, fr. L. testa an earthen pot, the skull. See Test a cupel, and cf. Testi[`e]re.]

1. A headpiece; a helmet. [Obs.]

The shields bright, testers, and trappures. --Chaucer.

2. A flat canopy, as over a pulpit or tomb. --Oxf. Gross.

3. A canopy over a bed, supported by the bedposts.

No testers to the bed, and the saddles and portmanteaus heaped on me to keep off the cold. --Walpole.

Source: Webster's Revised Unabridged Dictionary (1913)