was scared half to deathColloquial expression emphasizing that someone was extremely frightened or startled. แทบแย่ literally means “almost badly” and intensifies ตกใจ.
TH: เมื่อกี้มีเสียงดังมาก ฉันตกใจแทบแย่
EN: There was a really loud noise just now—I was scared half to death.