The term CHI LEAD-IN is composed of two words, 'CHI' and 'lead-in'. CHI is a Greek letter that is often used to represent the 22nd letter of the Greek alphabet. It is also used in mathematics and physics to represent various constants and functions. Lead-in is a term used to describe the introduction or beginning of something, such as a story or an event. The crossword solutions for this term are PHI (3 letters) and TAI (3 letters). PHI is another Greek letter, representing the 21st letter of the Greek alphabet. TAI is a Chinese word meaning 'GREAT' or 'GRAND'.