Nymphs making uninteresting commercials (6)
I believe the answer is:
dryads
'nymphs' is the definition.
(dryads are tree nymphs in Greek myth)
'uninteresting commercials' is the wordplay.
'uninteresting' becomes 'dry' (dry can mean dull or boring).
'commercials' becomes 'ads' (advertisements).
'dry'+'ads'='DRYADS'
'making' is the link.
(Other definitions for dryads that I've seen before include "Tree nymphs" , "Wood nymphs of legend" , "spirits" , "Nymphs of the woods" , "Tree-nymphs." .)