An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Geophysics: A layer of the atmosphere or the sea, regarded as lying between horizontal planes.
Geology: A single bed of → sedimentary rock, generally consisting of one kind of matter representing continuous deposition.

From L. stratum "thing spread out, pavement," from neuter p.p. of sternere "to spread out, lay down, stretch out," from PIE base *ster- "to spread, extend, stretch out;" cf. Pers. gostar-, gostardan "to spread;" Av. star- "to spread," starati "spreads;" Skt. star- "to spread out, extend, strew," strnati "spreads;" Gk. stornumi "I spread out," strotos "spread, laid out;" Ger. Strahlung "radiation," from strahlen "to radiate," from Strahl "ray;" from M.H.G. strāle; from O.H.G. strāla "arrow,stripe."

Ciné "layer," from cin present stem of cidan "to collect, gather;" Mid.Pers. cyn- "to gather, collect," Parthian Mid.Pers. (+*ni-) ncyn- "to pile up, heap up together," nycnyšn "stack;" Av. ci- (caē-, caii-) "to heap up, gather;" cf. Skt. ci- "to gather, heap up," cinoti "gathers."