They call themselves Welsh in English and Cymry in Welsh. Another term might be Cambrians.
The Welsh name for their country is "Cymru."
teisen
meistr
the word rucksack is from the German language
Yes. That is the correct spelling of rucksack. It means a knapsack or backpack.
By themselves - the Welsh By the English - the Taffs +++ Believe it or not, most of we English call you Welsh, "Welsh" too! :-) "Taff" presumably from the South Welsh river of that name?
tenau is thin.
Welsh
I know for a fact that people in Wales are called Welsh.
A synonym for rucksack is knapsack. +++ Also 'backpack' (may be hyphenated).
A rucksack or (backpack, haversack, knapsack, packsack) is a bag carried by a strap on your back or shoulder.