(adj.) Visually appealing, but not drop deadgorgeous. You wouldn't be embarrassed to be seen out in public with someone who's Combine Hot, but you also wouldn't brag about 'em.
"We don't want super hot girls, because they don't work hard enough. Give us some good ol' Combine Hot to make it through service, brah."
When having sex with a condom and the condom slips off inside of the person receiving the giver retrieves the end of the condom and instead of removing blows it up into a balloon.
Lisa: the condom is inside of Me!!!
Jim: Hold still it's time for the Columbia balloon!!!