the word 'turtleneck' is a compound noun formed from two english words, 'turtle' and 'neck'. it is a metaphorical construction from the late 19th century, where the high, fold-over collar of a garment was humorously compared to the long, retractable neck of a turtle. the term 'turtle' itself has a complex history, originally referring to the turtle dove in middle english before being applied to the shelled reptile. the compound effectively visualizes the garment's defining feature, creating a durable and intuitive name for this style of clothing.

Structure: turtle + neck turtle (english, from middle english 'turtel' or 'tortu', referring to the turtle dove, later extended to the reptile; here used for its perceived shape). neck (english, from old english 'hnecca', meaning the part of the body connecting the head and the shoulders; here used literally).