Short of breath crossing river, and understanding (8)
I believe the answer is:
grasping
'understanding' is the definition.
(to grasp something is to understand it)
'short of breath crossing river and' is the wordplay.
I cannot quite see how this works, but
'river' could be 'r' (abbreviation for river) and 'r' is found within the answer.
'breath' could be 'gasp' (I've seen this before) and 'gasp' is located in the remaining letters.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for grasping that I've seen before include "avaricious attitude" , "Greedy, avaricious" , "Miserly; seizing" , "Acquisitive - understanding" , "Holding" .)