If you are visiting a mediaeval castle and find a room labelled as "Garderobe", you will find that it is a toilet not a wardrobe.
Words that are etymologically the same includes:
head - chef - capital - cape (headland meaning, not coat meaning) - captain - (dumb)kopf
I'm not quite sure about kaput (broken) though. It is said to come from French capot, which I think is the same as cape in the coat meaning, which is rather than cape in the headland meaning.
Many dialects (particularly Central American ones) of Spanish have dropped the g entirely and now pronounce it as wah- even though the gua- spelling is retained.
I would say "particularly the southern cone". The G is pronounced very hard in -gua- words in Guatemala, (and not just in the name of the country, which in early texts is often seen as Coatemala).