IPA: /ˈkɔːkɪn/
KK: /ˈkɔːkɪn/
A small projection or spike on the sole of a shoe, often used for better grip or traction, especially in sports or on slippery surfaces.
The athlete wore shoes with calkins to improve his grip on the wet track.
The word 'calkin' originates from Middle English 'calkin', which is a diminutive form of 'calk' (meaning to make watertight or to seal). It refers specifically to a small calk or a device used to provide traction on the shoes of horses or to seal something.
Think of a small 'calk' that helps to 'seal' or provide grip — that's what a 'calkin' is.