of or having to do with the biceps muscle in the front of the upper arm or at the back of the thigh: a bicep injury
A biceps, especially of the front upper arm.Usage Note: The anatomical term for the muscle is biceps. The usual plural form of this word is identical to the singular: one biceps, two biceps. The word bicep is a back-formation created out of the mistaken impression that biceps is a regular English plural formed by adding -s to a singular noun. It is widely considered an error.