to start talking, to speak, to tell, to propose, to suggest, to break the ice
Example sentences
そんな事言い出すとは思わなかったよ。
I didn't expect that to come from you.
うちの弟は、よく寝ぼけて変なことを言い出す。
My little brother gets delirious when he's sleepy. He says the weirdest things.
彼は彼女を昼食に誘おうと言い出した。
He proposed asking her to lunch.