The quality or state of being single, or separate from all others; the opposite of doubleness, complication, or multiplicity.

Freedom from duplicity, or secondary and selfish ends; purity of mind or purpose; simplicity; sincerity; as, singleness of purpose; singleness of heart.

the quality of concentrating on one central objective; "his singleness of purpose"

without hypocrisy; "the singleness of his motives could not be questioned"