[TA] a fibrous band formed by the thickened inferior border of the aponeurosis of the external oblique that extends from the anterior superior spine of the ilium to the pubic tubercle, bridging muscular and vascular lacunae; forms the floor of the inguinal canal; gives origin to the lowermost fibers of internal oblique and transversus abdominis muscles.aponeurosis of external oblique (muscle). SYN: ligamentum inguinale [TA], arcus inguinalis*, crural arch, fallopian arch, fallopian ligament, femoral arch, Poupart ligament.