Employer from America meeting the queen (4)
I believe the answer is:
user
'employer' is the definition.
(someone who employs or uses something)
'america meeting the queen' is the wordplay.
'america' becomes 'US' (United States).
'meeting' says to put letters next to each other.
'the queen' becomes 'ER' (short for Elizabeth Regina ie Queen Elizabeth).
'us'+'er'='USER'
'from' acts as a link.
(Other definitions for user that I've seen before include "One taking advantage" , "Person employing something" , "One exploiting others" , "Exploiter (of others)" , "Drug addict (informal)" .)