Aware ruler should receive present (7)
I believe the answer is:
knowing
'aware' is the definition.
(I've seen this before)
'ruler should receive present' is the wordplay.
'ruler' becomes 'king' (king is a kind of ruler).
'should receive' indicates putting letters inside.
'present' becomes 'now' (both can mean the current period).
'king' placed around 'now' is 'KNOWING'.
(Other definitions for knowing that I've seen before include "Being acquainted with" , "Arch" , "Understanding" , "Being aware of" , "Wise" .)