One of a pair guided through river with hesitation (10)
I believe the answer is:
tweedledum
'one of a pair' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'guided through river with hesitation' is the wordplay.
I cannot quite see how this works, but
'guided' could be 'led' ('lead' can be a synonym of 'guide') and 'led' is found in the answer.
'river' could be 'tweed' (river in Scotland) and 'tweed' is found within the answer.
'hesitation' could be 'um' (sound made when hesitating) and 'um' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tweedledum that I've seen before include "He accused his brother of spoiling his rattle" , "Twin spoiling for a fight" , "The one who alleged that the other was a rattle spoiler" , "One of Carroll's twins" , "Twin of 9 dn" .)