A cap attachment is a type of clothing accessory that is used to secure a hat or cap to the head. The three crossword solutions for the term 'cap attachment' are PLUME (5 letters), EARLAP (6 letters), and earflap (7 letters). A PLUME is a feather or cluster of feathers worn as an ornament on a hat or cap. An EARLAP is a piece of cloth or fur attached to a hat or cap to cover the ears. An earflap is a piece of cloth or fur attached to a hat or cap to cover the ears and part of the neck.