The 'Ů' character is new. The lower case version is 'ů'.
It represents the vowel sound found in words like:
put
book
nook
good
tush
This is a tricky sound. It is a "tweener" vowel. Don't confuse it with an /u/ [IPA (ʌ)] or an \oo\ [IPA (u)]. It is between those two vowel sounds. Think of 'putt' vs 'put'. 'Putt' (golf putt) uses the \u\ sound like in 'mud'.