Side issue is a term used to describe a problem or issue that is not the main focus of attention, but still needs to be addressed. The crossword solutions for this term are BYE (3 letters) and THORN (5 letters). BYE is an informal way of saying goodbye, while THORN is a sharp object that can cause pain or injury. Both words can be used to describe a side issue, as they both represent something that can cause difficulty or disruption, even though it is not the main focus.