Basic clip (6)
I believe the answer is:
staple
I believe this clue is a double definition.
'basic' is the first definition.
(synonyms)
'clip' is the second definition.
(I've seen this before)
(Other definitions for staple that I've seen before include "It holds fast" , "U-shaped wire to fasten papers together" , "Fastening wire" , "The food one normally eats" , "Paper securer; main" .)