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

1) Someone or something that observes.
2) Idealized person or piece of equipment, often hypothetical, that measures relevant properties of a physical system.

Agent noun, from → observe + → -or.

A place located either at the top of the tube of a large telescope from where one observes or at the back of the tube where instruments are attached to the → Cassegrain focus.

→ observer; → cage.

General: Something that serves or is used in serving.
Computers: A computer software application that carries out some task on behalf of users. When users connect to a server, they can access programs, files, and other information from the server. Common servers are Web, mail, and database servers. A single computer can have several different server programs running on it.

Server, agent noun from serve, from M.E. serven, from O.Fr. servir "to serve," from L. servire "to serve," originally "be a slave," related to servus "slave;" cognate with Av. har- "to guard, watch," harətar- "guardian," hāra- "caring for;" Mid./Mod.Pers. zinhâr "protection, security; beware! mind!"

Zâvar "attendant, servant" (Dehxodâ), zâvari "attendance, service" (Dehxodâ), maybe related to Skt. sev- "to attend upon, serve," sevā- "service, attendance, worship," sevati "serves, attends," sevaka- "attendant, servant, follower."