Eccentric caught with line (5)
I believe the answer is:
crank
'eccentric' is the definition.
(I know that crank is a type of eccentric)
'caught with line' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'with' means one lot of letters go next to another.
'line' becomes 'rank' (rank is a kind of line).
'c'+'rank'='CRANK'
(Other definitions for crank that I've seen before include "Person with strange ideas, or machine part" , "Wind (up) - oddball" , "Person of eccentric habits" , "Turn (engine handle); eccentric" , "Turn a handle - weirdo" .)