Psychic put fear into underground worker (4,6)
I believe the answer is:
mind reader
'psychic' is the definition.
(someone with psychic powers)
'fear into underground worker' is the wordplay.
'fear' becomes 'dread' (synonyms).
'into' is an insertion indicator.
'underground worker' becomes 'miner' (someone working underground in a mine).
'dread' inserted into 'miner' is 'MIND-READER'.
'put' acts as a link.
(Other definitions for mind reader that I've seen before include "I know what you're thinking!" , "one knows what he is thinking" , "Thought interpreter" , "Man with intuition" , "one seeing things?" .)