Lewis & Short

2. in-vīsus, a, um, adj.

  1. I. Unseen: sacra maribus non invisa solum, sed etiam inaudita, Cic. Har. Resp. 27, 57: morbus, unknown, Cato, R. R. 141, 2: invisus atque inaccessus in id tempus saltus, Flor. 4, 12, 27.
  2. II. Adv.: invīsē, without being seen (post-class.): invise advenerat, Fulg. Myth. 3, 6.