The term 'whoop it up' is a phrase used to describe an enthusiastic celebration or PARTY. The crossword solutions for this term include 'CELEBRATE' (9 letters), 'ROISTER' (7 letters), 'CAROUSE' (7 letters), 'YELL' (4 letters), 'REVEL' (5 letters), 'FROLIC' (6 letters), and 'PARTY' (5 letters), and 'makemerry' (9 letters). All of these words are synonyms for the phrase 'whoop it up' and can be used to describe a lively and joyous gathering.