The crossword solutions for the term 'MOST PLENTIFUL' are AMPLEST and FATTEST. The word 'amplest' is an adjective meaning abundant or plentiful, while 'fattest' is an adjective meaning having the most fat. Both words can be used to describe something that is in abundance or has a large amount of something. Therefore, the term 'MOST PLENTIFUL' can be used to describe something that is abundant or has a large quantity of something.