Shot captures Ruby, first to tender bet (7)
I believe the answer is:
predict
'bet' is the definition.
(thesaurus)
'shot captures ruby first to tender' is the wordplay.
'shot' becomes 'pic' (short for picture).
'captures' indicates putting letters inside.
'ruby' becomes 'red' (synonyms).
'first to' suggests taking the first letters.
The first letter of 'tender' is 't'.
'pic' going around 'red' is 'predic'.
'predic'+'t'='PREDICT'
(Other definitions for predict that I've seen before include "Foretell, prophesy" , "Divine" , "Prophesy - portend" , "Foresee" , "Anticipate" .)