The /z/ sound is spelled with <z>, <s> or <se>. The /m/ sound is spelled with <m>, <mm>, or <mb> in dumb. Many of the pairs arise from contrasting a word ending in -m with a plural or 3rd-person -s. Notice how the homograph does makes pairs with dome and dumb.
This is a contrast between an alveolar sibilant fricative and a bilabial nasal continuant. It is not a problem.
One mildly taboo word pair is buzz/bum.
Interesting pairs include:
The mean density value is 1.1%. The list makes 146 semantic distinctions, a loading of 78%.
adders Adam anthers anthem A's aim as am baas balm balsas balsam banters bantam blaze blame blazed blamed blazing blaming blues bloom boos boom booze boom boozed boomed boozing booming borders boredom breeze bream brewers brougham brews broom B's beam bees beam bunkers bunkum buzz bum buzzed bummed buzzing bumming cars calm cause corm chars charm chatters Chatham cholers column cobbers Cobham confers confirm cookers Cookham cores corm cries crime crows chrome C's seam C's seem days dame daze dame dies dime dodgers dodgem does dome does dumb do's doom doze dome dozed domed D's deem fez fem fills film firs firm flays flame flues flume foes foam fours form frays frame fuse fume fused fumed fusing fuming gays game gaze game gazed gamed gazing gaming glees gleam glues gloom gnaws norm grisly grimly has ham haws haulm hazard hammered hells helm his him hoes home hosing homing infers infirm I's I'm jazz jam jazzed jammed jazzing jamming knows gnome K's came laser lamer lays lame lazed lamed lazing laming lies lime lingers lingam Liz Lymm loos loom losing looming lows loam L's elm Mays maim mazed maimed millers Millom muzzy mummy neighs name O's ohm overs ovum parrs palm parse palm parsed palmed parsing palming phase fame phased famed phrase frame phrased framed phrasing framing position permission pries prime prise prime prised primed prising priming purrs perm puzzle pommel puzzled pommelled puzzles pommels rectors rectum resigned remind resource remorse resourceful remorseful resourcefully remorsefully rise rhyme rising rhyming rose Rome rose roam R's arm rues rheum ruse rheum screes scream seas seam seas seem sees seam sees seem seize seam seized seamed seizing seaming seize seem seized seemed seizing seeming sisters system spews spume spurs sperm stores storm Swazi swami Swazis swamis swiz swim teas team teas teem tease team teased teamed teasing teaming tease teem teased teemed teasing teeming thatchers Thatcham ties thyme ties time tizzy Timmy toes tome Tsar mar Tsars mars twos tomb viz vim wars warm whirrs worm whiz whim whores haulm whose whom woos womb Z Med zap map zapped mapped zapping mapping zaps maps zee me Zen men zest messed zinc mink zone moan zoned moaned zones moans zoning moaning zoo moo zoos moos zoos zoom
John Higgins, Shaftesbury, November 2010.