Here's what rhymes with ffifth.
fifth Words that almost rhyme with ffifth
ifs riffs whiffs gives lives myths cliffs sieves scythes skiffs sniffs writhes smiths forgives hieroglyphs monoliths blacksmiths goldsmiths silversmiths myth width filth pith scythe writhed writhe sixth smith plinth labyrinth therewith wherewith herewith hyacinth forthwith monolith silversmith