Here's what rhymes with counteravail.
fail sale sail avail veil hail shale vale assail hale faille male scale mail pale tail tale jail nail rail frail gale whale bail stale travail wail bale dale pail snail flail kale unveil countervail wale trail prevail email curtail inhale quail quale braille topsail grail wassail hightail lugsail carrell detail entail exhale bewail derail gunwale mainsail pigtail foresail impale taffrail bobtail pellmell ponytail monorail hangnail tattletale fingernail martingale nonpareil swallowtail