Can a mere learner navigate on one? (5)
I believe the answer is:
'navigate on one?' is the definition.
I can't tell whether this definition defines the answer.
'can a mere learner' is the wordplay.
'mere learner' becomes 'l' (as in a learner driver with L-plates on their car. I am not sure about the 'mere' bit.).
Can you help me to learn more?
(Other definitions for canal that I've seen before include "Duct" , "Manmade flower" , "navigate this?" , "Man-made waterway" , "Inland waterway" .)