IPA: /əˌsoʊ.siˈeɪ.t̬ɪ.vɪ.ti/
KK: /əˌsoʊ.siˈeɪ.t̬ɪv.ɪ.ti/
The quality or state of being able to group things together in a way that the order of operations does not change the result.
In mathematics, the property of associativity allows us to add or multiply numbers in any order without changing the outcome.
Associativity → It is formed from "ad-" (meaning to) and "socius" (meaning companion or ally), combined with the suffix "-ity" (meaning the state or quality of). The word describes the quality of being associated or connected with companions or allies.
Think of 'companions' ('socius') being 'together' ('ad-') in a certain way — that's what associativity means.
No commonly confused words.