A.rope from the end of a sail-yard (τέρθρον), used for reefing, Ar.Eq.440, cf. Sch. ad loc.; “τ. κάλοι” Erot., Gal.19.145.
II.τερθρίαπνοή, cited from S. (Fr.333) in EM753.7, is there expld. by ὀπισθία, a stern wind, but perh. rather a stiff gale requiring the use of τέρθριοι.