Young woman in glasses (4)
I believe the answer is:
Here is my best explanation:
'young woman' is the definition.
(lass is a kind of young woman)
'in glasses' is the wordplay.
'in' indicates the answer is hidden within the clue.
'LASS' can be found hidden inside 'glasses'.
(Other definitions for lass that I've seen before include "Sweet resident of Richmond Hill?", "Girl (of Richmond Hill?)", "young girl?", "Young woman (-. Eng.)", "Sweetheart", "Familiar form of address for female", "Girl, young woman", "A girl", "Young woman, girl" and "She".)