bipennate

Adjective

bipennate (not comparable)

1. Of, pertaining to, or having the nature of a muscle, the fibres of which attach to a tendon on two sides (as a feather barbed on both sides).
   • It then follows that bipennate muscles generate even more force than unipennate ones of similar volume, and the force increases with the angle of pennation.1999, Christopher McGowan, A Practical Guide to Vertebrate Mechanics
   • Beneath the deltoid lies the external rotators of the shoulders, including the bipennate infraspinatus and the teres minor (Fig. 5-20B).2007, Neal S. Elattrache, Christopher D. Harner, Raffy Mirzayan, Jon K. Sekiya, editors, Surgical Techniques in Sports Medicine, page 50
2. Bipinnate (pinnate and having a pinnate leaflet).
   • Its bipennate leaves are composed of a slightly straightened general petiole, of four partial petioles, situated, two at the extremity of the proceeding, and convergent, two a little lower, and growing almost at right angles; each of them bearing more than twenty pairs of small horizontal petioles.1849, Adrien de Jussieu, James Hewetson Wilson, The Elements of Botany, page 501
   • But this Burnet Pimpinella is of a different (Umbelliferous) order, though similarly styled because its leaves are likewise bipennate.1897, William Thomas Fernie, Herbal Simples Approved for Modern Uses of Cure, 2006 Gutenberg eBook edition
3. Having two wings; bipennated.