An Etymological Dictionary of Astronomy and Astrophysics

1a) General: A shoot or arm-like limb of a tree; anything like a limb of a tree; any offshoot from a main trunk.

1b) Astro.:→ asymptotic giant branch;
→ blue horizontal-branch stars; → red giant branch; → branching; → branching ratio.

1c) Math.: Any of the two halves of a → hyperbola.

1d) Math.: A section of a curve separated by → discontinuity from the rest of the curve.

2a) To put forth branches.

2b) To spread in branches.

Etymology (EN): M.E., from O.Fr. branche, from L.L. branca “a claw, paw.”

Etymology (PE): 1) Šâxé “branch,” from Mid.Pers šâk, cf. Mod.Pers. šâx, šax “branch; horn,” Skt. sakha- “a branch, a limb,” Arm. cax, Lit. šaka, O.S. soxa, PIE *kakhâ “branch.”

2. Šâxé zadan with verb zadan “to strike, beat,” → outcrop.