wombo combo [wahm-boh-kahm-boh]
1. Competitive Gaming. Original Reference Can Be Viewed HERE.
2. League of Legends Slang. An especially good combo of abilities, especially ultimate abilities, between two or more champions on the same team.
EX. In League of Legends, there are a lot of potential wombo combos. For example, Ashe Ult and Ezreal Ult, as seen HERE. Creating combos in your team comp can turn team fights in a pinch with the most simple, to my mind, being Miss Fortune's Ult combo'd with Sona's Ult; the latter freezes your opponents in place and MF's Ult does a serious cone of damage on top of them. Combine that with an Amumu Ult for more stun and damage, a Rumble Ult for slow and damage, and Karthus Ult to finish anyone lucky enough to run away with health.
I could go on...