Member
Middle English: via Old French from Latin membrum ‘limb’.
wiktionary
From Middle English membre, from Old French membre, from Latin membrum(“limb, body part”), from Proto-Indo-European *mḗms, *mēms-rom(“flesh”). Akin to Gothic 𐌼𐌹𐌼𐌶( mimz, “meat, flesh”), Crimean Gothic menus.
Coexists with native Middle English lim, limb(“member, limb, joint”) (from Old English lim(“limb, joint, main branch”)), and displaced Middle English lith(“limb, joint, member”) (from Old English liþ(“limb, member, join, tip”)).
See remember.
etymonline
member (n.)
c. 1300, "body part or organ, an integral part of an animal body having a distinct function" (in plural, "the body"), from Old French membre "part, portion; topic, subject; limb, member of the body; member" (of a group, etc.)," 11c., from Latin membrum "limb, member of the body, part," probably from PIE *mems-ro, from root *mems- "flesh, meat" (source also of Sanskrit mamsam "flesh;" Greek meninx "membrane," mēros "thigh" (the "fleshy part"); Gothic mimz "flesh").
In common use, "one of the limbs or extremities." Especially "the sex organ" (c. 1300, compare Latin membrum virile, but in English originally of women as well as men). Figurative sense of "anything likened to a part of the body" is by 14c., hence "a component part of any aggregate or whole, constituent part of a complex structure, one of a number of associated parts or entities."
The transferred sense of "person belonging to a group" is attested from mid-14c., from notion of "person considered in relation to an aggregate of individuals to which he or she belongs," especially one who has united with or been formally chosen as a corporate part of an association or public body. This meaning was reinforced by, if not directly from, the use of member in Christian theology and discourse from mid-14c. for "a Christian" (a "member" of the Church as the "Body of Christ"). Meaning "one who has been elected to parliament" is from early 15c.
