Meaning "group, club" is from 1540s, originally of associations of persons for some specific purpose. Meaning "people bound by neighborhood and intercourse aware of living together in an ordered community" is from 1630s. Sense of "the more cultivated part of any community" first recorded 1823, hence "fashionable people and their doings." The Society Islands were named 1769 by Cook on his third Pacific voyage in honor of the Royal Society, which financed his travels across the world to observe the transit of Venus.
Proto-Indo-European root meaning "to follow."
It forms all or part of: associate; association; consequence; consequent; dissociate; ensue; execute; extrinsic; intrinsic; obsequious; persecute; persecution; prosecute; pursue; second (adj.) "next after first;" second (n.) "one-sixtieth of a minute;" sect; secundine; segue; sequacious; sequel; sequence; sequester; sociable; social; society; socio-; subsequent; sue; suit; suite; suitor; tocsin.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit sacate "accompanies, follows;" Avestan hacaiti, Greek hepesthai "to follow;" Latin sequi "to follow, come after," secundus "second, the following;" Lithuanian seku, sekti "to follow;" Old Irish sechim "I follow."