tartar / tarter 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. 👇
tartar: (noun) an incrustation that forms on the teeth and gums.
tarter: NA
tartar: t·AA·r·t·er
tarter: t·AA·r·t·er
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)