DECE'ITFULNESS, noun 1. Tendency to mislead or deceive; as the deceitfulness of sin. 2. The quality of being fraudulent; as the deceitfulness of a man's practices. 3. The disposition to deceive; as, a man's deceitfulness may be habitual.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI