The word "temporalis" is a direct borrowing from Medieval Latin, where it served as the adjectival form for the temple of the head. Its primary root is the Latin noun tempus, which intriguingly held two distinct meanings: "time" and "temple." The connection is thought to be poetic or physiological; the temples were where time was felt to pass, evidenced by the pulsing of blood vessels. In anatomical terminology, temporalis was nominalized to specifically designate the broad, fan-shaped muscle that overlies the temporal bone. Thus, the term's logic flows from the ancient body part (temple) to the modern, precise anatomical structure associated with it.

Structure: temporal (relating to time or the temples) + is (adjective/noun suffix) - temporal: From Latin temporalis, from tempus (genitive temporis) meaning "time" or "temple of the head." In this anatomical context, it refers to the "temple." - is: A Latin suffix used to form adjectives and nouns, often indicating a relationship or pertaining to.