Je was op zoek naar: privit (Sloveens - Engels)

preverite, ali je tesno privit.
make sure that the adapter is fitted tightly.

vrhnji del je privit na matico.
the top part is screwed onto the nut.

privit je na spodnji del in drži celotno aparaturo trdno na steklenici.
it is screwed into the lower part, holding the entire apparatus firmly onto the bottle,