Reckon caught in it, one's hooked (6)
I believe the answer is:
addict
'one's hooked' is the definition.
I can't judge whether this definition defines the answer.
'reckon caught in it' is the wordplay.
'reckon' becomes 'add' (reckon can mean to calculate).
'caught' becomes 'c' (cricket abbreviation).
'in' indicates putting letters inside.
'c' put inside 'it' is 'ict'.
'add'+'ict'='ADDICT'
Can you help me to learn more?
(Other definitions for addict that I've seen before include "One is dependant on a chemical substance" , "One who's hooked" , "Devotee: user" , "One hooked on drugs" , "Regular drug user" .)