The term 'OF ALL' can be solved by the crossword solutions LEAST (5 letters) and MOST (4 letters). LEAST is an adverb that means to the smallest degree or extent, while MOST is an adverb that means to the greatest degree or extent. These two words are often used together to describe the extremes of a situation. For example, one might say 'He is the LEAST qualified of all the applicants' or 'She is the MOST qualified of all the applicants'.