noctivagant
Walking or wandering in the nighttime, nightwandering.
[…] I therefore think, Sarah, that the incommensurability of the crime with the effect, completely warrants the supersaliency of this noctivagant delinquent.
Where it comes from
From Late Latin noctivagans, from noctivagare, from Latin nocti- (“night”) + participle form of vagari (“to wander”).
Adapted from the Wiktionary entry noctivagant (CC BY-SA 4.0).