The Worst, Lowest, Worst, Nasty, Terrible
Adverb, Noun, な adjective, and の adjective
さいてい
よくこんな最低最あくの酒がのめるよね。
How can you drink such terrible, garbage alcohol?
今までで最低のキスだったかも。
Maybe it was the worst kiss ever.
えぇっ！あの試験で最低点を取ったの？参ったなぁ。
Wow, I can’t believe you got the lowest score on the test. What a bummer!
The most low is the lowest. It's also what you call something when you think it's the worst or just plain terrible. Try yelling this out when you're disgusted about someone or something.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.