The term 'pack like sardines' is a phrase used to describe a situation where people or objects are crammed into a small space. The two crossword solutions for this term are 'CRAM' (4 letters) and 'JAM' (3 letters). Cramming is the act of packing something tightly, while jamming is the act of pushing something into a tight space. Both words can be used to describe the same concept of packing something into a small space, as if it were a can of sardines.