It's high in distortion (3)
I believe the answer is:
tor
'it's high' is the definition.
I can't tell whether this defines the answer.
'in distortion' is the wordplay.
'in' says the answer is hidden in the clue.
'TOR' is hidden within 'distortion'.
Can you help me to learn more?
(Other definitions for tor that I've seen before include "Rot on rocky peak" , "Rocky outcrop" , "A rocky hill in Devon" , "High, rocky, bare hill" , "Dartmoor peak" .)