the button used to fasten the collar down on a garment
collar button in American English
noun
a button or stud for fastening a detachable collar to the neckband of a shirt or for fastening together the ends of a collar or neckband
Word origin
[1885–90, Amer.]This word is first recorded in the period 1885–90. Other words that entered Englishat around the same time include: reactor, toner, twofer, upsweep, zoom
Examples of 'collar button' in a sentence
collar button
We looked down and between us on the floor was an exquisite pearl collar button.