forehead

It means the forehead. There are two clues. 1) Usually, when eyebrows are meant, the word "eyebrow" will be used. 2) Brow CAN mean forehead, eyebrow, or the ridge just above the eyebrows. But the forehead is the only one that can "crinkle." A crinkled brow, wrinkled brow, or furrowed brow means horizontal lines on the forehead. They are created by muscular action, and usually indicate that someone is puzzled or worried.