sinter claes

Etymology
Probably from.

The -er in the first component is of uncertain origin. Suggested to be due to the influence of other saints' names, such as Sinter Meis (from Sint Remeis) and Sinter Makel (from Sint Remakel). Also suggested is that sinter is a feminine dative form of sint, from the expression. Otherwise thought to be a dialectal form of sint or from an earlier *sinten(e) (from sint Ni-). Compare also modern Dutch.

Also suggested to be a contraction of +  +, calqued from. This has, however, been disputed.

Proper noun

 * 1) Saint Nicholas, Sinterklaas