Could one teach a trout to swim? (5)
I believe the answer is:
tutor
'could one teach a' is the definition.
I can't judge whether this definition defines the answer.
'trout to swim?' is the wordplay.
'to swim?' indicates anagramming the letters (I've seen 'swims' mean this).
'trout' anagrammed gives 'TUTOR'.
Can you help me to learn more?
(Other definitions for tutor that I've seen before include "college teacher" , "Private instructor" , "Edify" , "Personal teacher" , "Give individual instruction" .)