The term 'jet set' refers to a group of wealthy and fashionable people who travel frequently by private jet. The crossword solutions for this term are 'ELITE' (5 letters), 'SSTS' (4 letters), 'airplanes' (9 letters), and 'GLITTERATI' (10 letters). ELITE is an adjective used to describe the highest social class, while SSTS stands for 'supersonic transport systems, ' which are aircraft that can fly faster than the speed of sound. Airplanes are the vehicles used to travel, and GLITTERATI is a term used to describe the glamorous lifestyle of the jet set.