More suitable for one on the assembly line (6)
I believe the answer is:
fitter
This could be a double definition.
'more suitable' is the first definition.
('fit' can be similar in meaning to 'suitable')
'one on the assembly line' is the second definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for fitter that I've seen before include "Workman" , "Tradesman being in better shape" , "less likely to feel fatigue" , "A skilled technician" , "Worker assembling machinery - more healthy" .)