precedence / precedents are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
precedence: (noun) status established in order of importance or urgency.
precedents: (noun) an example that is used to justify similar occurrences at a later time. (noun) a subject mentioned earlier (preceding in time).
precedence: p·r·EH·s·ah·d·ah·n·s
precedents: p·r·EH·s·ah·d·ah·n·t·s
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)