One of my favorite words is τὸ πέλωρ. The first of its two occurrences in the Odyssey is in apposition to Κύκλωψ ‘Cyclops’ (referring to Polyphemus, the only such creature with which Odysseus comes into contact):
“τοὺς ἀκέων συνέεργον ἐυστρεφέεσσι λύγοισιν,
τῇς ἔπι Κύκλωψ εὗδε πέλωρ, ἀθεμίστια εἰδώς,
“Without speaking, I fastened [the rams] together with well-twisted osier-twigs,
on which the Cyclops—the monster, expert in lawlessness—slept,
taking them three at a time” (Od. 9.427–429)
The other occurrence is of a creature no less deserving:
“ἔνθα δ᾽ ἐνὶ Σκύλλη ναίει δεινὸν λελακυῖα. 85
τῆς ἦ τοι φωνὴ μὲν ὅση σκύλακος νεογιλῆς
γίγνεται, αὐτὴ δ᾽ αὖτε πέλωρ κακόν· οὐδέ κέ τίς μιν
γηθήσειεν ἰδών, οὐδ᾽ εἰ θεὸς ἀντιάσειεν.”
“Scylla dwells in there, shrieking awfully. 85
Her voice is like that of a new-born puppy,
though she herself is an evil monster; nobody would laugh
upon seeing her, not if it were a god coming face-to-face with her.” (Od. 12.85–88)
But the sole use of πέλωρ in the Iliad makes a curious departure from the image of man-killing creatures who do not abide by the laws set by the gods.
ἦ, καὶ ἀπ᾽ ἀκμοθέτοιο πέλωρ αἴητον ἀνέστη
χωλεύων· ὑπὸ δὲ κνῆμαι ῥώοντο ἀραιαί.
[Hephaestus] spoke, and the terrible monster rose from his anvil,
limping; his frail legs hastened underneath him. (Il. 18.10–11)
The god of the forge, Hephaestus, is rising to greet Thetis, the mother of Achilles, who will ask him to make a shield for her son. Hephaestus is famously lame in both feet, ever since an unfortunate event in his past. He limps everywhere, unable to walk in a normal manner, and is frequently the butt of the other gods’ jokes because of this. In these lines we get a cartoon-like portrayal of Hephaestus, with his legs (technically, his κνῆμαι ‘lower legs’; cf. κνημῖδες ‘greaves‘) fluttering about in frantic circuits only to convey him across the room at an unremarkable pace. Whether or not we are to understand πέλωρ αἴητον ‘terrible monster’ as being ironic for so unthreatening a character, it is worth asking whether it is Hephaestus’ disability, his deviation from what is considered normal physiology, that licenses this use of πέλωρ.
Beyond the noun, its derived adjectives πέλωρος and πελώριος are applied to creatures, gods (Hades, Ares), heroes (Ajax, Hector, and Achilles), and things that are inhuman or prodigious in some way, or deviate majorly from what is considered to be normal for a human.
A derived noun πελωρίᾱ yields the term ‘peloria‘ in modern botany, denoting an aberrant type of floral growth.
The word πέλωρ itself is, like a sizable minority of the Homeric vocabulary, taken from the Aeolic dialect. Evidencing this fact is an Attic-Ionic cognate τέλωρ that apparently existed as well. Just like the first sound in Aeolic πίσυρες ‘four’ (Ionic τέσσαρες and Attic τέτταρες), the first consonant of πέλωρ/τέλωρ goes back to Proto-Indo-European *kʷ-. (Aeolic lacks the Attic-Ionic exception where *kʷ becomes *t, not *p, before a front vowel.) The second consonant is the result of dissimilation from final ρ; the reconstructed form for Aeolic πέλωρ is therefore *kʷér-ōr-, built on the well-attested root *kʷer- ‘do, make, build.’
A second Greek word from this same root is τὸ τέρας ‘sign, portent’ < PIE *kʷér-h̥2s-. Whatever the connection between this term and the PIE sense of ‘make, do,’ it is worth pointing out that ‘portent, omen’ is a common first step in the semantic evolution of words meaning ‘monster’; cf. Latin monstro ‘show, point out’ and monstrum ‘sign, omen; monster, monstrosity’ (for the former semantics of monstrum cf. German Muster and Dutch monster, both ‘sample, template’; also English pass muster = “be deemed satisfactory according to a standard”); also, perhaps, δράκων ‘dragon, serpent’ from the zero-grade of the same root as δέρκομαι ‘see, behold.’
What is the semantic connection between *kʷer- ‘make’—whence Sanskrit कृणोति kṛṇoti ‘do,’ कर्म karma ‘deed’; Persian كردن kærdæn ‘do,’ كار kār ‘work’; Old Irish cruth ‘form, shape’—and πέλωρ, which so often is best translated ‘monster, prodigy’? (*kʷer- is apparently also the root underlying such Balto-Slavic words as Lithuanian kẽras ‘sorcery,’ Polish czar ‘magic, spell,’ Russian чары ‘spells, charms.’) Perhaps the meaning of τέρας ‘portent’ was chronologically intermediate, following ‘something made (by a god?)’ but preceding ‘monster’?