n. 1. 1768 UK sl. – a term of address to a man
n. 2. 1823 – anything abnormally large of its kind; a big lie; a heavy blow
n. 3. 1827 Amer. dial. – a driver of animals; a drover; an ox or mule driver
n. 4. 1861 Eng. dial. – a shake; a shiver
n. 5. Bk1942 Amer. sl. – something excellent
n. 6. 1960s Aust. sl. – a fool
n. 7. 1980s US sl. – a masturbator
n. 8. 20C US sl. – a gadget, a thing
n. 9. 20C US sl. – the penis
vb. 1703 Eng. dial. – to tremble, to shake with cold, fear, etc.
from whack (vb.) + -er
EXAMPLE (for n.3)
“…A noisy train of long-horned, thin-bodied oxen, dragging trailed wagons piled high with freight from the railway terminus, comes round the corner, and stops to listen before unyoking for the night, the whacker’s long whip cracking like pistol-shots as he lashes his unwieldy beasts into position…”
From: Harper’s New Monthly Magazine
No. CCCLIX – April, 1880 – Vol. I.X.
La Villa Real De Santa Fe