Often drilled around part of plant (7)
I believe the answer is:
tendril
'part of plant' is the definition.
(I've seen this before)
'often drilled around' is the wordplay.
'around' indicates the answer is hidden within the clue.
'TENDRIL' can be found hidden inside 'often drilled'.
(Other definitions for tendril that I've seen before include "Climbing plant's attachment" , "Plant extrusion" , "Plant attachment for climbing N wisp of hair" , "Climbing plant's gripper" , "Climbing plant's grasper" .)