I realise this is an old question but it came up when I was searching for a solution to this problem today. I figured out a single-formula solution which I'm sharing in case it helps anyone else looking for this.
This works if you want the last word, and the string is separated by spaces. Basically it's 3 steps, nested:
ReverseString([Name]) - reverses the whole string
GetWord(<string>, 0) - this gets the first word of the string
ReverseString - reverse the word back to normal
You could probably modify it to get multiple words but it's a bit more fiddly... e.g. this gets the last 2 words, although you have to manually add the space and so you get an extra space if there is only one word in the string: