Weaker person could be unusually grounded (8)
I believe the answer is:
underdog
'weaker person' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'unusually grounded' is the wordplay.
'unusually' indicates anagramming the letters.
'grounded' is an anagram of 'UNDERDOG'.
'could be' is the link.
Can you help me to learn more?
(Other definitions for underdog that I've seen before include "Unfancied performer" , "Likely loser" , "One thought to have little chance of winning" , "unlikely winner" , "Lower-rated competitor" .)