Exact historical dictionary sense
Brilliant in Webster's 1913 dictionary
The 1913 record labels brilliant as adjective. Its source-bounded etymology and selected historical definition appear below.
[F. brillant, p. pr. of briller to shine or sparkle (cf. Pr. & Sp. brillar, It. brillare), fr. L. beryllus a precious stone of sea-green color, Prov. It. brill. See Beryl.]
Cross-verified historical senseIn Webster's Revised Unabridged Dictionary (1913), "brilliant" is labeled adjective. Its etymology is recorded as: "[F. brillant, p. pr. of briller to shine or sparkle (cf. Pr. & Sp. brillar, It. brillare), fr. L. beryllus a precious stone of sea-green color, Prov. It. brill. See Beryl.]" The selected historical definition says: "Sparkling with luster; glittering; very bright; as, a brilliant star."