ichor: the substance that flowed in the veins of the Immortals instead of blood.
The First Trojan War: Heracles was enraged at being cheated by Laomedon (father of Priam). Laomedon had promised him some special horses for his help in building Troy, but welshed after the job was done. Heracles returned with some Greek chums (including Telamon father of Ajax - and the young Philoctetes) and quickly flattened it.
Bellerophon: grandfather of Glaucus and Sarpedon. King Proetus' wife fancied him but he refused her. She accused him of rape, and Proetus sent him away to Lycia, with "a folded tablet on which were traced a number of devices with deadly meaning". The Lycian king, however didn't kill him, but despatched him on various quests (including the Chimaera)- which he performed so well that he inherited the kingdom.
xenoi : guest-friends. Such friendships are the most important social bonds in pre-civilised society, as Glaucus and Diomedes indicate. Because of this xenia between the families, they cannot fight. Zeus Xenios was the protector of this relationship, and the the Trojan war is ultimately about his punishment of the guest Paris for abusing the trust of his host Menelaus (Book 13)
Hector's and Ajax's gifts. According to tradition (not recorded by Homer) both of these gifts were deadly. Ajax's belt was used to tie Hector behind Achilles' chariot; while Ajax used Hector's sword to kill himself with, after Achilles' arms were awarded to Odysseus.
Boars' Tusk Helmet. Amazingly such a helmet was found at Cnossos, in Crete. It is almost exactly as described by Homer here.