SIN'GLENESS, noun 1. The state of being one only or separate from all others; the opposite of doubleness, complication or multiplicity. 2. Simplicity; sincerity; purity of mind or purpose; freedom from duplicity; as singleness of belief; singleness of heart.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI