An Etymological Dictionary of Astronomy and Astrophysics

1. A support component of a gyroscope, which allows the axis to move freely.
   
2. A mechanical mounting frame having two mutually perpendicular axes of rotation.

Etymology (EN): Gimbal, alteration of gemel “twin,” from M.E., gemelles, from O.Fr. gemeles (Fr. jumeau, jumelle), from L. gemellus, diminutive of geminus “twin;” cf. Pers. Kermâni dialect jomoli “twin;” → Gemini.

Etymology (PE): Doqâb, from do “two” (Mid.Pers. do; Av. dva-; cf.
Skt. dvi-; Gk. duo; L. duo; O.E. twa; Ger. zwei) + qâb “frame,” from Turkish.