The term 'EXTREMELY HAPPY' can be expressed in many different ways. One way is to use the 8-letter word 'ECSTATIC, ' which means to be overwhelmed with joy and excitement. Another way is to use the 6-letter word 'ELATED, ' which means to be filled with joy and pride. The 8-letter word 'BLISSFUL' also expresses this feeling, as it means to be in a state of perfect happiness. The 7-letter word 'INORBIT' is another way to express extreme happiness, as it means to be in a state of great joy and delight. The 8-letter word 'MERRIEST' is another way to express this feeling, as it means to be in the happiest state possible. The 9-letter word 'DELIGHTED' is another way to express extreme happiness, as it means to be filled with joy and pleasure. The 11-letter word 'ONCLOUDNINE' is another way to express this feeling, as it means to be in a state of great joy and contentment. Finally, the 15-letter word 'ONTOPOFTHEWORLD' is another way to express extreme happiness, as it means to be in a state of complete joy and satisfaction.