First and second covered in wager (4)
I believe the answer is:
best
'first' is the definition.
(similar in meaning)
'second covered in wager' is the wordplay.
'second' becomes 's' (common abbreviation).
'covered in' indicates putting letters inside.
'wager' becomes 'bet' (synonyms).
's' placed into 'bet' is 'BEST'.
'and' is the link.
(Other definitions for best that I've seen before include "George -, footballer" , "Cream of the crop" , "Superlative" , "Supreme" , "The most talented" .)