Many of you may not know this 
but you can sometimes mix two welsh words together to form a new word (bathu gair newydd)…
Cyfansoddair itself is such a word (Cyfansoddi - to compose + Gair - a word)
I was curious if anyone here knows any or if they have any particular favourites they would like to share?
Unfortunately I cannot share right now … Off my head, I can only think of ones used by friends in the past that are far too rude to publish publicly haha
One I’ve always liked is llosgfynydd - volcano, or literally “burning mountain”
Hyfryd.
Here’s another / Dyma un arall
Llywoden - Computer mouse
Llyw = steering wheel /// llygoden = mouse
Clever hey? Many speakers will just say llygoden if pressed for an answer but I have seen this in academia and technical discussion
We also see Llyw in Llywelyn - as llyw can refer to a person being a leader (someone who steers things).
Diminutive form of Llywelyn is Lelo … fyi
Full translation of Llyw
Perhaps “Canolbwyntio”: literally “pointing to the centre”. It means “to concentrate”. Love it!
arfordir, ar + mor + tir
on + sea + land
= coast
llwybr arfordirol, coastal path
I hadn’t seen that before, but I like it! 
It was discussed on the termau newydd threads back in the mists of the early internet. Like many Welsh language documents…Im struggling to find them on search engines again