Leaders in The Oval Office, also (3)
I believe the answer is:
too
'also' is the definition.
(synonyms)
'leaders in the oval office' is the wordplay.
'leaders in' indicates taking the first letters.
The first letters of 'the oval office' is 'TOO'.
(Other definitions for too that I've seen before include "Unduly" , "Likewise" , "Also; overly" , "Furthermore" , "As well; in addition" .)