The term 'to a large extent' can be summarized using the crossword solutions 'MOSTLY' (6 letters) and 'QUITE' (5 letters). Both of these words are adverbs that indicate a degree of something, usually used to describe how much or how often something is done. 'MOSTLY' implies that something is done in a large majority, while 'QUITE' implies that something is done to a significant degree. Therefore, the term 'to a large extent' can be summarized as 'done MOSTLY or QUITE a lot'.