Cleared obstacle limiting American power (5)
I believe the answer is:
leapt
'cleared' is the definition.
The definition and answer can be both to do with motion as well as being past participle verbs.
Perhaps you can see an association between them that I can't see?
'obstacle limiting american power' is the wordplay.
'obstacle' becomes 'let' ('let' could historically mean an obstruction).
'limiting' is an insertion indicator.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'power' becomes 'p' (symbol in physics).
'a'+'p'='ap'
'let' placed around 'ap' is 'LEAPT'.
Can you help me to learn more?
(Other definitions for leapt that I've seen before include "Made spring" , "Jumped on plate" , "moved up quickly" , "Took off" , "Jumped a long way" .)