ἀνεπαίσθητος
From LSJ
Περὶ τοῦ ἐπέκεινα τοῦ νοῦ κατὰ μὲν νόησιν πολλὰ λέγεται, θεωρεῖται δὲ ἀνοησίᾳ κρείττονι νοήσεως → On the subject of that which is beyond intellect, many statements are made on the basis of intellection, but it may be immediately cognised only by means of a non-intellection superior to intellection
English (LSJ)
ον,
A unperceived, imperceptible, Ti.Locr. 100b, Plu.2.1062b, Luc.Sat.33. Adv. -τως Simp. in Cat.309.3. 2 Act., not perceiving, τινός Plb.28.1.6, Longin.4.1. OGI194(Egypt. Adv. -τως Ph.Fr.70H., Hippiatr.38, Svrian. in Metaph.100.38, Simp. in Ph.1198.39.