Conjecture rhymes with:
lecture, acupuncture, architecture, fracture, infrastructure, juncture, lecture, manufacture, picture, prefecture, puncture, remanufacture, restructure, stricture, structure, superstructure, telepicture, tincture
Conjecture sounds like:
canister, cannister, cannistraro, canstar, chemistry, communicator, connecter, connector, consider, constar, construe