Answer: coulda

AnswerCrossword Clue
COULDA"I .. been a contender!"
COULDAMight have, slangily
COULDA"I .. been a contender"
COULDA"... Been the One" (2006 Rihanna song)
COULDAPart of an "if only ..." lament
COULDAMight have, informally
COULDA'I -- been a contender'
COULDAWoulda partner
COULDAJust might have, slangily
COULDAMight've, informally