The term 'persist in' can be expressed in four different ways using crossword solutions. The first is 'KEEP', which is a four letter word meaning to remain in the same state or position. The second is 'keepat', which is a six letter word meaning to continue doing something with determination. The third is 'keepon', which is also a six letter word meaning to continue doing something despite difficulties. The last is 'standto', which is a seven letter word meaning to remain firm in one's purpose or opinion. All of these words express the idea of continuing to do something despite obstacles or challenges.