Definitions for unlined
Random House Webster's College Dictionary
not having a lining or liner
"a thin unlined jacket"
seamless, unlined, unseamed(adj)
smooth, especially of skin
"his cheeks were unlined"; "his unseamed face"
without lining; without liner
the bitter wind made me wish I hadn't opted for this unlined coat
unmarked by lines, especially of the skin
even on her 70 birthday her skin remains unlined