American extended period in employment (5)
I believe the answer is:
usage
'employment' is the definition.
(I know that employment can be written as usage)
'american extended period' is the wordplay.
'american' becomes 'US' (United States).
'extended period' becomes 'age' (age is a kind of period. I am not sure about the 'extended' bit.).
'us'+'age'='USAGE'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for usage that I've seen before include "Accepted or habitual practice" , "Treatment; tradition" , "Tradition - rate of consumption" , "Acceptable language" , "Application" .)