The /ʃ/ sound is spelled with <sh>, <su>, <ch> or <ti>. The /m/ sound is spelled with <m>, <mm> or <mb> in lamb.
This is a contrast between a voiceless alveolar fricative and a voiced bilabial nasal continuant. It is not a problem.
Taboo word pairs include shag/mag and shat/mat.
Interesting pairs include:
shoulder moulder
shyness minus
The mean density value is 1.8%. The list makes 126 semantic distinctions, a loading of 58%.
ash am assure amour assures amours Boche bomb cache cam cash cam chaise Mays chaise maize chaise maze chaises mazes chassis massy chic meek chute moot chutes moots clash clam clashing clamming clashed clammed crash cram crashing cramming crashed crammed crush crumb crushed crumbed dash dam dashing damming dashed dammed dash damn dashing damning dashed damned dish dim dishing dimming dished dimmed douche doom flesh phlegm gush gum gushing gumming guished gummed hash ham hashing hamming hashed hammed harsh harm hush hum hushing humming hushed hummed lash lam lashing lamming lashed lammed lash lamb lashing lambing lashed lambed mash ma'am mashes mammies mush mum mushy mummy pasha Parma pasha palmer pashas palmers plush plum plush plumb plusher plumber plushy plummy plushier plummier plushiest plummiest posh pom poshes pommies rash ram rush rum rushy rummy sash Sam schist missed schist mist schists mists Sean morn Sean mourn shack mac shacks macs shacks Max shad mad shade made shade maid shades maids shag mag shags mags shaggy Maggie shah ma shahs Mars shake make shakes makes shaking making shaker maker shakers makers shake-up make-up shake-ups make-ups shakings makings shale mail shale male shallow mallow shallows mallows shame maim shamed maimed shaming maiming shames maims shammy mammy shandy Mandy shanks Manx shard marred share mare shares mares shark mark sharks marks sharks Marx shat mat shatter matter shattered mattered shattering mattering shatters matters shawl mall shawls malls shawl maul shawls mauls she me shed Med sheen mean sheen mien sheet meat sheets meats sheet meet sheeting meeting sheets meets shear mere shears meres sheer mere sherry merry shilling milling shine mine shines mines shining mining shingle mingle shingled mingled shingles mingles shingling mingling shire mire shires mires shirk murk shoal mole shoals moles shoaled mould shock mock shocked mocked shocking mocking shocks mocks shocker mocker shockers mockers shockingly mockingly shod Mod shoe moo shoeing mooing shoes moos shoo moo shooed mooed shooed mood shoot moot shooting mooting shoots moots shop mop shopped mopped shopping mopping shops mops shore maw shores maws shore more shored Maud shorn morn shorn mourn shorter mortar shortest morticed shoulder moulder shouldered mouldered shouldering mouldering shoulders moulders show mo show mow showing mowing shows mows shown mown showed mowed showed mode shown moan shuck muck shucked mucked shucking mucking shucks mucks shuffle muffle shuffled muffled shuffles muffles shuffling muffling shuffler muffler shufflers mufflers shut mutt shuts mutts shutter mutter shuttered muttered shuttering muttering shutters mutters shy my shyness minus slash slam slashing slamming slashed slammed slush slum slushy slummy slushier slummier slushiest slummiest sure moor swish swim swishing swimming thrush thrum tosh Tom trash tram wish whim