And yes, this word is listed in the OED, with the definition "a neighbor whose house is on fire".

Ucalegon's name isn't just a name; in Greek it means "not to have a care" (ouk = 'not', alego = 'to have a care', or 'to take heed'). The Greek Oukalegon becomes Ucalegon in Latin.

The shepherd climbs the cliff, and sees from far
The wasteful ravage of the wat'ry war.
Then Hector's faith was manifestly clear'd,
And Grecian frauds in open light appear'd.
The palace of Deiphobus ascends
In smoky flames, and catches on his friends.
Ucalegon burns next: the seas are bright
With splendor not their own, and shine with Trojan light.
Virgil, Aeneid 2.311.