Sigmaform rhymes with:
insituform, spongeform, insituform, spongeform, alarm, arm, barnstorm, biopharm, brainstorm, charm, chloroform, coliform, conform, cuneiform, deform, disarm, disinform, dorm, ducharme, farm, firearm, firestorm, forearm, form, freeform, gendarme, genpharm, hailstorm, harm, inform, insituform, landform, lukewarm, maidenform, misinform, nonfarm, norm, novopharm, orme, outperform, perform, platform, rainstorm, rearm, reform, sandstorm, schwarm, sharm, sidearm, snowstorm, spongeform, storm, swarm, thunderstorm, torme, transform, unarm, underarm, underperform, uniform, warm, windstorm
Sigmaform sounds like:
sambrano, san-fran, sanborn, schimberni, schoenborn, sonneborn, sunburn