Heather being entertained by Americans (5)
I believe the answer is:
erica
'heather' is the definition.
(the plant genus Erica includes heather plants)
'entertained by americans' is the wordplay.
'entertained by' indicates the answer is hidden within the clue.
'ERICA' can be found hidden inside 'americans'.
'being' acts as a link.
(Other definitions for erica that I've seen before include "I care (anag) - plant - girl" , "Shrubs" , "ling" , "Female" , "Woman" .)