Falling Rock Clan (in an area prone to avalanches)
High Death (living in the mountains, they see themselves as 'above' the lowlands they raid)
Red Night Reavers (like many darkvision-having races, they like to raid at night, and 'paint the night red' with the blood of their victims)
Garnok's Goblin-Stompers (a rite of passage among the warriors is to capture a goblin and stomp it to death during the initiation in an enthusiastic drug-enhanced war-dance. As local goblin populations have waned, it's become acceptable to buy one from slavers, rather than go out and hunt one up personally...)
If this particular orc clan has a favored weapon or a favored god or a favored animal, a name based on that could serve as an identifier.
Spear Runs Red clan uses spears, preferentially, and even has a surprisingly well-organized second line of longspear wielding females who follow their menfolk into battle and strike at foes their mates are fighting face to face.
Black Wing clan has females and elders who train ravens to harry their targets in battle. It's a relatively minor advantage, since ravens kinda suck in combat, but it's their signature 'thing,' and now that they've begun to hatch a brood of bloodhawks, they might surprise the heck out of the next group to dismiss their feathered friends as a minor nuisance.
The Boar Tusk Raiders train war boars. Being a mountain clan, perhaps mountain goats would make more sense... Ram's Horn Raiders?
In 1st edition, from what I recall, all of the orc tribe names seemed to be graphic descriptions of something on their war-banners, like Bloody Hand Clan or Burning Eye or Black Mailed Fist Company.