From Longman Dictionary of Contemporary Englishdeceitfulde‧ceit‧ful /dɪˈsiːtfəl/ adjective TRICK/DECEIVEsomeone who is deceitful tells lies in order to get what they want His manner was sly and deceitful. —deceitfully adverb His lawyer argued that his client had not acted deceitfully. —deceitfulness noun [uncountable]
Examples from the Corpusdeceitful• He got the contract, but only by being deceitful.• None the less, the effort of the sociologists to exonerate welfare as a special cause of the ghetto crisis was statistically deceitful.• Being deliberately deceitful about the Government's policies has become something of a habit for the Labour party.• There was something deceitful and impatient about the smiling look in his eyes.• The wilfulness of human nature can be deceitful, and we can hang on to old ways like cherished thoughts or possessions.• A deceitful day that makes one think of lilacs and daffodils, before blasting you with another cannonade of winter.• The Center for the Study of Commercialism considers product placement a deceitful form of advertising.• a deceitful man• The company has engaged in deceitful practices for years.• I don't trust her. I think she has a deceitful smile.• Even in prayer, his heart was fickle and deceitful, turning this way and that.