noun, plural cer·tain·ties.
- the state of being certain.
- something certain; an assured fact.
- for/of a certainty, certainly; without a doubt: I suspect it, but I don’t know it for a certainty.
noun plural -ties
- the condition of being certain
- something established as certain or inevitable
- for a certainty without doubt
c.1300, certeynte, “surety, pledge,” from Anglo-French certeinté (late 13c.), Old French certainete “certainty,” from Latin or Vulgar Latin *certanitatem (source of Old Spanish certanedad); see certain. Meaning “that which is certain” is attested from early 14c.; meaning “quality of being certain” is from mid-14c.