Article I had to keep partner excited (8)
I believe the answer is:
animated
'excited' is the definition.
(animating is a kind of exciting)
'article i had to keep partner' is the wordplay.
'article' becomes 'an' (indefinite article).
'i had' becomes 'id' (I'd).
'to keep' is an insertion indicator.
'partner' becomes 'mate' ('mate' can be a synonym of 'partner'**).
'id' going around 'mate' is 'imated'.
'an'+'imated'='ANIMATED'
(Other definitions for animated that I've seen before include "Enlivened (like a cartoon film)" , "in cartoon form" , "full of beans" , "Vivacious in diamante" , "Diamante (anag)" .)