1the dead skin at the base of a fingernail or toenail:you’ve been gnawing at your cuticles
2the outer cellular layer of a hair:the cuticle is the hair’s protective shield
3 Botany & Zoology a protective and waxy or hard layer covering the epidermis of a plant, invertebrate, or shell: [count noun]:the body is covered with a non-living cuticle of chitin