That's not a thing. But a ten-syllable word might be considered decasyllabic.
no word it isn't possible because if you take away one syllable from a five syllable word you get a four syllable word and there is no such thing as a "no syllable word"
Three is a one syllable word. That syllable is sometimes silent.
Crumb is a one syllable word.
No, it is a two syllable word: stead-y