The word you're looking for is "compound words". English has a couple too -- i.e. bedtime, nowadays, etc -- but in english it's generally considered poor grammar to invent your own while in languages like dutch and german it's mandatory. That said the longer ones tend to be never used, in dutch "tafeltennistafelfabrikantenvereniging" is a popular example translating to "table tennis table manufacturers meeting", but you'll be hard pressed for a situation where that word is called for!

I always wondered how to actually type out nowadays... all those spellcheckers had me convinced it was now days with a lil mumbling in between.

I think that's a reasonable assumption.