tick3
n.
(
in phr. on tick)
on credit.
Etymology
C17: appar. short for ticket in the phr. on the ticket, referring to a promise to pay.
tick4
n.
a fabric case stuffed with feathers or other material to form a mattress or pillow.
▸short for ticking.
Etymology
ME: prob. Mid. Low Ger., MDu. tēke, or MDu. tīke, via W. Gmc from L. theca ‘case’, from Gk thēkē.