A lover's keepsake, perhaps, is a trinket or item that a couple exchanges to remember their love for one another. It could be something as simple as a piece of jewelry, a photograph, or a handwritten note. The term 'TRESS' is a five-letter word that can refer to a woman's hair, which is often seen as a symbol of beauty and femininity. In this context, it could be used to describe a lock of hair given as a token of love.