An Etymological Dictionary of Astronomy and Astrophysics

1. Chem.: To add as much of a liquid, solid, or gas to a solution as it can absorb at a given temperature.
   
2. To fill something with so many things that no more can be added.

Etymology (EN): From L. saturatus, p.p. of saturare “to fill full, sate, drench,” from satur “sated, full,” from PIE base *sā- “to satisfy.”

Etymology (PE): Anjâlidan “to saturate, to fill” (Dehxodâ, Steingass), ultimately from Proto-Iranian *ham-gar-, from *ham- “together,” denoting “much, many,”
→ syn-, + *gar- “to soak, moisten;” cf. Sogdian wγyr- “to soak, steep,” from *aua-gar-, from which derives Pers. âqâridan, âqeštan “to steep, soak; mix.”