The term HIGH SIGN is composed of four words, each with a different number of letters. The first word is SIGNAL, which is a 6-letter word that means to communicate a message or an idea. The second word is NOD, which is a 3-letter word that means to move the head up and down in agreement or acknowledgement. The third word is ALARM, which is a 5-letter word that means a WARNING SIGNAL or sound. The fourth word is WARNING, which is a 7-letter word that means a cautionary statement or indication of potential danger. The final word is SKIAREABOUNDARY, which is a 15-letter word that refers to the boundary of a ski area.