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