Fine fancy lingerie needs navy lacework (8)
I believe the answer is:
filigree
'lacework' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for filigree that I've seen before include "Ornamental lacework in gold or other metal" , "Delicate ornamental metal work in gold or silver" , "Delicate tracery" , "Ornamental wirework" , "Delicate ornamental metalwork" .)