Hint to capture rook against deviating line (5)

I believe the answer is:
curve
'line' is the definition.
(curve is a kind of line)
'hint to capture rook against' is the wordplay.
'hint' becomes 'cue' (cue can mean a hint or prompt).
'to capture' indicates putting letters inside.
'rook' becomes 'R' (chess abbreviation).
'against' becomes 'v' (abbreviation for 'versus').
'r'+'v'='rv'
'cue' placed around 'rv' is 'CURVE'.
'deviating' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for curve that I've seen before include "way of learning" , "Not the straightforward" , "that may be hyperbolic" , "Line that's not straight" , "Arch" .)
