The term 'unimportance' can be defined by four crossword solutions: INSIGNIFICANCE (14 letters), pettiness (9 letters), IRRELEVANCE (11 letters), and inconsequence (13 letters). INSIGNIFICANCE refers to the lack of importance or value, while pettiness implies smallness or triviality. IRRELEVANCE means that something is not applicable or pertinent, and inconsequence suggests that something has no bearing on the outcome. Together, these words describe a state of unimportance, where something is of little or no consequence.