underspill Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition verb. to spill or overflow from below. Example Sentence The underspill from the overflowing dam caused minor flooding in the nearby fields. More Example Sentences The cup began to underspill with juice. Synonyms spill; overflow; leak Antonyms surplus; excess Hear It! Say It! Write It! underspill Switch to cursive Start Share with your friends: