The crossword solution for the term 'TO THE EXTENT THAT' is a four-letter word, 'SO'. The phrase 'to the extent THAT' is used to indicate the degree or amount to which something is true. It is often used to introduce a clause THAT explains the conditions under which something is true. For example, 'I will help you to the extent THAT I am able.' In this sentence, the speaker is indicating THAT they will help, but only to the degree THAT they are able.