The term 'fill to satisfaction' can be summarized by two crossword solutions: 'SATIATE' (7 letters) and 'SATE' (4 letters). Both words are derived from the Latin verb 'satiare, ' which means 'to fill or satisfy.' SATIATE is a more formal word, often used in literature, while SATE is more informal and is used in everyday speech. Both words refer to the act of satisfying a need or desire, usually through the consumption of food or drink.