Insignificance is the state of being too small or too unimportant to consider or worry about. If something fades into insignificance, it suddenly feels tiny next to something bigger. The word is a little formal. In daily talk, people more often say it doesn't matter or it's no big deal. Though actually, we mostly use this noun for things, feelings, or problems — 'a sense of insignificance' — not as a label you pin on a person like a name.