Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
trixāgo or trissāgo, ĭnis, f., a plant, called also chamaedrys, germander: Teucrium chamaedrys, Linn.; Plin. 24, 15, 80, § 130; Veg. Vet. 1, 17; 1, 42 al.