Talking quickly; rapid speech that may be hard to understand.
彼は早口で話すので聞き取りにくい。
He speaks so fast that it's hard to catch what he says.
この早口言葉は舌がもつれて難しい。
This tongue-twister is difficult because it makes the tongue get tied.
緊張すると早口になってしまう人もいる。
Some people start speaking quickly when they get nervous.