de·ceit·ful \-tfəl\adjective Etymology: Middle English desaitful, from desait, deceite deceit + -ful 1.: having a tendency or disposition to deceive : given to deception : dishonest < she was a deceitful scheming little thing — Israel Zangwill > 2.: tending to deceive : deceptive, misleading < smooth, shining, and deceitful as thin ice — S.T.Coleridge > Synonyms:see dishonest