The crossword solutions for the term COMPLETELY OR ENTIRELY are ALL, which is a three-letter word. It is an adverb that means to the greatest degree or extent, without exception or qualification. It is often used to emphasize the totality of something, such as when someone says they are 'all in' for an activity or event. It can also be used to indicate the entirety of a group or collection, such as when someone says they have 'all the answers'.