Thersilochus (Ancient Greek Θερσίλοχος) was a Paeonian captain fighting for Troy. Hector rallies him among the allies over Patroclus' body; Achilles later slays him with many of his countrymen on the banks of the Scamander.
Adapted from Wikipedia, "Thersilochus" · CC BY-SA 4.0
I.In the Iliad
In Iliad 17 Hector heartens Thersilochus among Paeonian and other allies in the fight for Patroclus. In Iliad 21 Achilles kills him in the river slaughter of the Paeonians.
Wikipedia's Thersilochus page also lists an Antenorid Trojan and a Dulichian suitor under the same name. The atlas id thersilochus-paeonian is the Homeric Paeonian only — not thersilochus-dulichium.
II.Homonyms
Distinct from the Dulichian suitor of Penelope and from Virgil's Italian warrior slain by Turnus. Treat Antenorid attributions on the Wikipedia page as a separate (or confused) strand, not this Paeonian captain.