Significance is the weight a thing carries — why it matters, what it stands for beyond itself. A date circled on a calendar for a reason only one person in the house knows; a cheap gift that means far more than it cost.
It runs three ways. There is importance: 'a decision of real significance'. There is meaning: 'the significance of the red thread in the film', what the thing points at. And there is the statistical one you meet in every research paper, where a result is significant when it is unlikely to be chance — a technical claim about probability, not a claim that the finding is large or interesting. The adjective is significant and the verb is signify. It takes OF: the significance of the date. And 'significant other' is a mildly official way of saying partner, on forms that would rather not guess.
1nounsignificanceThe importance or weight of something.
“Nobody understood the significance of the meeting until years afterwards.”
synonyms: importance
2nouncarriesThe meaning something carries, especially a deeper or hidden one.
“She asked what the significance of the red thread was.”
3nounstatisticsIn statistics: the degree to which a result is unlikely to have happened by chance.
“The difference between the two groups never reached significance.”
significance is a measure of importance.
Also accepted in games: importance
Significance came through Middle and Old French from Latin significantia. English once had a doublet of it, signifiance, borrowed a little earlier from the same French stock; significance outlived it and took the whole field. Signify, significant and signal all lean on the Latin word for a sign.
Proto-Indo-European
*dʰeh₁-
Latin
significantia
Old French
significance
Middle French
significance
Middle English
significaunce
English, today
significance
Middle English significaunce, from Middle French significance, from Old French significance, from Latin significantia. a doublet of signifiance.
Etymology from Wiktionary, CC BY-SA
Practised in Big Ideas, Academic English