Meaning of “nail” - Learner’s Dictionary

nail

noun [ C ] us uk /neɪl/
METAL OBJECT

B2 a thin piece of metal with a sharp end, used to join pieces of wood together:

a hammer and nails

More examples

FINGERS/TOES

B2 the hard surface at the end of your fingers and toes:

to cut your nails
Stop biting your nails.

(Definition of “nail noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)