'Sinew' is PIE *sey- (to bind) — literally 'thebinder,' tissue connecting muscle to bone.
Definition
A piece of tough fibrous tissue uniting muscle to bone; a tendon. Also used figuratively to mean strength or the essential source of strength.
The Full Story
GermanicOld Englishwell-attested
From OldEnglish sinu, seonu ("sinew, tendon, nerve"), from Proto-Germanic *sinwō ("sinew, tendon"), from PIE *sneh₁-wr̥ or *seh₁-nw-, related to the root *sneh₁- ("to spin, sew, bind"). This root is preserved in Sanskrit snāvan- ("sinew, tendon"), Latin nervus ("sinew" — from earlier *snervus with s-mobile loss), and Avestan snāvarə ("sinew"). The connection to binding is semantically transparent: tendons
Did you know?
In the KingJames Bible, the phrase 'the sinews of war' (meaning money and resources needed for combat) translates Cicero's 'nervos belli' — where Latin 'nervus' meant both 'sinew' and 'nerve.' The confusion between sinews (tendons), nerves, and ligaments persisted in European languages for centuries: German 'Sehne' means both 'sinew' and 'bowstring,' and English 'nerve' once meant 'sinew' (hence 'nervous' originally meant 'sinewy, strong').
pre-industrial materials, used for bowstrings, thread, and binding. The metaphorical extension to "strength, muscular power" (the sinews of war, sinews of the state) appeared in Middle English and became a standard rhetorical figure. The spelling sinew (with final -ew) developed in Middle English, probably by analogy with other -ew words. The PIE root also contributed, through different extensions, to Latin sēriēs ("chain, row") and possibly to needle (via the sewing sense). Key roots: *sey- (Proto-Indo-European: "to bind, to tie").