Lewis & Short

prŏbātĭo, ōnis, f. [probo].

  1. I. A trying, proving; a trial, inspection, examination (class.): athletarum probatio, Cic. Off. 1, 40, 144: futura, id. Verr. 2, 1, 54, § 142; Varr. R. R. 1, 20, 1: oesypi, Plin. 29, 2, 10, § 36: croci sinceri, id. 21, 6, 17, § 32: pumicis, id. 36, 21, 42, § 155: gemmae recusant limae probationem, id. 37, 13, 76, § 200: equitum, a review, Val. Max. 2, 2, 9.
  2. II. In partic.
    1. A. Approbation, approval, assent (class.): ob probationem pretium datum, Cic. Font. 4, 17: tale visum nullum esse ut perceptio consequatur, ut autem probatio, multa, i. e. the assent of belief, though not the direct evidence of the senses, id. Ac. 2, 31, 99.
    2. B. Proof, demonstration (post-Aug.), Quint. 5, 10, 8: firma, id. 11, 3, 2: potentissimae, id. 5, 10, 103: ad cujus rei probationem immittit indices, Just. 32, 2, 9: oculorum, ocular demonstration, Plin. 2, 2, 2, § 5.
    3. C. In partic., in rhet., the third part of a discourse, also called confirmatio or fides orationis, in which the orator enumerates his arguments, Quint. 3, 9, 1.