An Etymological Dictionary of Astronomy and Astrophysics

The figure of the → Moon or an → inferior planet when it is less than half illuminated, as seen by the → observer.

Etymology (EN): From O.Fr. croissant, from L. crescentum, p.p. of crescere “to grow, increase; spring forth,” from PIE base *ker- “to grow” (cf. Gk. kouros “boy,” kore “girl,” Pers. dialects Laki korr “son, boy,” Lori kor “son, boy,” Malayeri kora “boy,” Kordi kur “son,” Arm. serem “bring forth,” serim “be born”).

Etymology (PE): Helâl from Ar. Barn “the new moon,” from Proto-Iranian *aparnâ- “unfilled,” from negation prefix → a- + parnâ- “full;” cf. Mid.Pers. purr mâh “full moon,” Av. pərənô-mâh- “full moon,” Skt. purna-mâs- “full moon;” → full;
→ moon.