περιληπτῶς → conceivably, comprehensibly, by perception, by mental apprehension

[spiros]

περιληπτῶς → by direct perception, by mental apprehension

[billberg23]

Attested only in Epicurus, Letter to Herodotus (Diogenes Laertius 10.40.5): παρὰ δὲ ταῦτα οὐθὲν οὐδ' ἐπινοηθῆναι δύναται οὔτε περιληπτῶς οὐτ' ἀναλόγως τοῖς περιληπτοῖς → beyond these things [bodies and space] nothing can be thought of, either conceivably or by analogy to what can be conceived.
Literally, "conceivably," "comprehensibly," from περιλαμβάνω "surround," "encompass."  Oddly similar to the English slang expression "wrap one's head/mind around" something.

[spiros]

Yes, "wrap one's head/mind around" is an interesting analogy.

wrap one's mind around → αντιλαμβάνομαι, βάζω στο κεφάλι μου, βγάζω άκρη, επεξεργάζομαι, καταλαβαίνω, κατανοώ, καταφέρνω να καταλάβω, καταφέρνω να κατανοήσω, καταφέρνω να χωνέψω, συλλαμβάνω, συνειδητοποιώ, χωνεύω, χωρά ο νους μου, χωράει ο νους μου