Here's what rhymes with photosynth.
plinth hyacinth labyrinth Words that almost rhyme with photosynth
since sins fins shins thins things skins hymns pins sings wins spins bins evince rinse tins chins mince wince gins shims begins kings prince rings wings limbs lymph twins swings nymph rims stings whims flings grins slings swims hairpins quince dims gyms skims tings wrings brings convince springs strings clings florins violins javelins brims trims minims pseudonyms underpins offsprings wellsprings fifth filth scythe myth sixth width pith smith writhed writhe forthwith therewith herewith wherewith monolith silversmith