The term 'kick up one's heels' is an idiom that means to have a good time, usually by dancing or partying. The crossword solutions for this term are REVEL (5 letters), GAMBOL (6 letters), and ROISTER (7 letters). REVEL means to take part in lively and noisy festivities, while GAMBOL means to frolic or skip about playfully. ROISTER means to engage in boisterous, drunken merrymaking. All three words refer to activities that involve having a good time and enjoying oneself.