Here's what rhymes with maintopgallantsail.
fail sale sail veil hail shale vale hale 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 wale detail prevail email travail inhale quail quale bewail derail mainsail topsail grail taffrail wassail hightail lugsail entail curtail exhale gunwale pigtail countervail foresail impale monorail bobtail nonpareil pellmell carrell ponytail martingale hangnail tattletale fingernail swallowtail