The term "Panhead" refers to a type of motorcycle engine produced by Harley-Davidson from 1948 to 1965. It is named for its distinctive valve covers, which resemble a frying pan. The Panhead engine is known for its durability and performance, featuring an overhead valve design that improved efficiency compared to earlier models. Panhead engines were popular among motorcycle enthusiasts and custom builders, contributing to the rise of the chopper culture in the 1960s. They are often sought after by collectors today due to their classic design and historical significance in the evolution of American motorcycles.