An Etymological Dictionary of Astronomy and Astrophysics

1. An applicant or suitable person for a position.
   

2. An astronomical entity which is being considered for belonging to a special class of entities; e.g. → black hole candidate, → dark matter candidate, → supernova candidate.

Etymology (EN): From L. candidatus “clothed in white” (reference to the white togas worn by those seeking office),
from candidus “shining white,” from candere “to shine,” cf. Skt. cand- “to shine,” candra “bright; the Moon;”
PIE base *kand- “to glow, to shine.”

Etymology (PE): Nâmzad, literally “nominated,” from nâm, → name,

• zad, p.p. of zadan “to strike” (Mid.Pers. zatan, žatan, O.Pers./Av. jan-, gan- “to strike, hit, smite, kill,”
  Skt. han- “to strike, beat,”
  Gk. theinein “to strike,” L. fendere “to strike, push,” Gmc *gundjo “war, battle;” PIE *g^when- “to strike, kill”).