Fair; barely (4)
I believe the answer is:
just
I believe this is a double definition.
'fair' is the first definition.
(I know that fair can be written as just)
'barely' is the second definition.
(synonyms)
(Other definitions for just that I've seen before include "And nothing more" , "Fair and proper" , "Barely; right and fair" , "This very minute" , "Fair - precisely" .)