Lewis Short
(verb) : an-năto (better adn-), āre
* To swim to or toward: ei insulae crocodili non adnatant,Plin. 8, 25, 38, § 93; Jan here reads adnant; Sil. 10, 610.—With ad: ad manum hominis adnatare,Plin. 9, 29, 46, § 87; 9, 10, 12, § 38.
* To swim along by or by the side of: comes lateri adnatat,Sen. Agam. 452.
Charlton T. Lewis, Charles Short, A Latin Dictionary