príastok

Could you please specify what sense of the word "príastok" you have in mind? It appears in different contexts in Slovak (and related languages) and could refer to something like an appendix or supplement, an attached component, or another specialized meaning in a particular field. If you indicate the intended meaning or field (for example: linguistic term, architectural/technical attachment, or a general concept), I can draft a concise, neutral wiki-style article under 300 words.