paintbrush is sivetxa

sivetxa = paintbrush (noun) (some things Google found for "sivetxa": a very rare term; name of an automated web script or bot; similar siveta.com is a Mexican website platform for business electronic transfers; similar Sivecha is a very rare last name; similar Sivech (aka Sivech-e Sofla) is the name of a village in western Iran)

Word derivation for "paintbrush"
Basque = brotxa, Finnish = sivellin
Miresua = sivetxa

This is the Mirusua word for paintbrush. The tx consonant combination in Miresua (as in Basque) is pronounced like ch. It'll be for either an artist's thin paintbush or a wide brush used to apply paint.

The Basque word for paintbrush brotxa appears to come the Spanish word brocha (or Catalan word brotxa). The Finnish word sivellin is derived from the Finnish verb sivellä meaning to stroke. Another word in Finnish for paintbrush is pensseli.

The word brush, as in paintbrush, occurs in Alice's Adventures in Wonderland.

Seven flung down his brush, and had just begun "Well, of all the unjust things--" when his eye chanced to fall upon Alice, as she stood watching them, and he checked himself suddenly: the others looked round also, and all of them bowed low.

"Would you tell me," said Alice, a little timidly, "why you are painting those roses?"