ummistaa

Could you clarify what you mean by "ummistaa"? Specifically, is this a Finnish verb, a place, a surname, or a fictional/technical term? If you mean the Finnish verb, do you want an encyclopedia-style article covering its definition, usage, etymology, and examples, and should I assume general language usage (linguistic context) or a specific field (e.g., medical, legal)? Once I have the context, I can draft a concise, neutral wiki-style entry under 300 words.