sooner UK /ˈsuːnə/US /ˈsunɚ/Sooner noun 3adverb 1forms 1phrases 1 Sooner noun3 •(informal) A native or resident of the American state of Oklahoma •(informal) A competitor representing the University of Oklahoma. •(historical) One who crossed into Indian territory before the official opening of settlement in the Oklahoma land rush, in order to obtain land sooner.Some skunk of a Sooner, sneaking in ahead of the Run, had set the blaze to keep the Boomers off, saving the land for himself. — 1930 adverb1 •rather.I would sooner die than marry you!Sooner than have a problem later, I made sure the policy was in order. formsSooners Phrases with sooner no sooner thanAt the moment when; instantaneously after; immediately after.