in de weer zijn

Dutch

Etymology

From weer in the sense of "defense". The original sense of the expression would be "to struggle for something", in time broadening to a more general sense of "being busy with something".

Verb

in de weer zijn

1. (idiomatic) to be busy, to work

   Ik ben al sinds 6 uur vanochtend in de weer. ― I've been busy since 6 AM.