make it clearThe て-form of はっきりさせる, meaning “to make clear” or “to clarify.” It can be used as a request or command; はっきりさせておく means “make it clear in advance” or “establish clearly.”
JA: 自分の気持ちをはっきりさせてから、彼に話そう。
EN: Let’s make our feelings clear before talking to him.