sinewous

From Middle English synewous, equivalent to sinew +‎ -ous.^[1]

sinewous (comparative more sinewous, superlative most sinewous)

1. (obsolete) Synonym of sinewy.
   • 1587 January, Raphael Holinshed, “The Description of Meilerius”, in The Second Volume of Chronicles: Conteining the Description, Conquest, Inhabitation, and Troublesome Estate of Ireland; […], 2nd edition, volume II, London: […] [Henry Denham] […] at the expenses of Iohn Harison, George Bishop, Rafe Newberie, Henrie Denham, and Thomas Woodcocke, →OCLC, page 38, column 1, lines 30–32:

     His armes and other moꝛe ſinewous than fleſhie, a ſtout and a valiant gentleman he was and emulous.

   • 1861, Neville Temple [pseudonym; Julian Fane]; Edward Trevor [pseudonym; Robert Bulwer-Lytton, 1st Earl of Lytton], Tannhäuser; or, The Battle of the Bards. A Poem., London: Chapman and Hall, […], →OCLC, page 13:

     [T]rothful men, who once / Look’d in his lordly, luminous eyes, and scann’d / His sinewous frame, compact of pliant power, / Aver he was the fairest-favour’d knight / That ever, in the light of ladies’ looks, / Made gay these goodly halls.