Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
albesco, ĕre, v. inch. [albeo], to become white (mostly poet. or in post-Aug. prose; once in Cic.), * Lucr. 2, 773; so Verg. A. 7, 528: albescens capillus, * Hor. C. 3, 14, 25: maturis messis aristis, Ov. F. 5, 357: aquilarum pennae, Plin. 10, 3, 4, § 13: flammarum tractus, Verg. G. 1, 367: mare, quia a sole collucet, albescit et vibrat, * Cic. Ac. 2, 33, 105.
Hence, of the appearance of daylight, of daybreak (cf. albeo), to dawn: lux, Verg. A. 4, 586: albescente caelo, Paul. Dig. 28, 2, 25.