eyelid

eyelid /ˈaɪˌlɪd/ noun
plural eyelids
eyelid
/ˈaɪˌlɪd/
noun
plural eyelids
Britannica Dictionary definition of EYELID
[count]
: either one of the two movable pieces of skin that cover your eye when it is closed — see picture at eye

not bat an eyelid

— see 4bat