The spelling of /b/ is always <b> or <bb> and /m/ is <m>, <mm> and <mb> in bomb and dumbly. Notice how the homograph bass enters pairs with mass and mace, and the pair bow/mow with its inflections involves a pair of homographs.
The contrast is between a plosive and a nasal continuant, both voiced and occupying the same place of articulation. There are plenty of opportunities for confusion even among native speakers. One of the most dangerous is the mishearing of million for billion or vice versa.
Taboo word pairs are bastard/mastered, bugger/mugger, bum/mum and boobs/booms.
Interesting pairs include:
The mean density value is 3.9%. The list makes 248 semantic distinctions, a loading of 52%.
Abe aim abuse amuse abused amused abuses amuses abusing amusing abyss amiss arboreal armorial arbour armour arbours amahs B me baa ma baa mar baa'd marred baas mars babel Mabel back mac backs macs bad mad badly madly badness madness bade mad badge Madge bag mag bags mags baggy Maggie bail mail bailed mailed bailing mailing bails mails bail male bails males bait mate baited mated baiting mating baits mates baize maize bake make bakes makes baking making baker maker bakers makers bald mauled bale mail baled mailed baling mailing bals mails bale male bales males ball maul balling mauling balls mauls balled mauled balm barb balm ma'am ban man banning manning banned manned bans mans bandy Mandy band manned bane main bangle mangle bangles mangles banish mannish banks Manx banner manner banners manners bar ma bar mar bars mars barred marred barring marring barbel marble barbels marbles bare mare bares mares bark mark barked marked barking marking barks marks barker marker barkers markers barley Mali barrow marrow barrows marrows Barry marry barter martyr bartered martyred bartering martyring barters martyrs base mace bash mash bashes mashes bashing mashing bashed mashed basin mason basins masons bask mask basked masked basking masking basks masks bass mass bass mace basses maces bastard mastered bat mat bats mats batted matted batting matting batch match batches matches bate mate bated mated bating mating bates mates batter matter battered mattered battering mattering batters matters bawd Maud bawdy Maudie bawl maul bawls mauls bawled mauled bawling mauling bay may bayed made be me beak meek bear mare bears mares beat meat beat meet beating meeting beatings meetings beats meets beau mo beau mow beaux mows bed Med bee me beer mere beers meres beg Meg Beith Meath bellow mellow bellowed mellowed bellowing mellowing bellows mellows belt melt belted melted belting melting belts melts ben men bend mend bended mended bending mending bends mends Benny many bent meant berry merry berth mirth beseems meseems Bessie messy bet met bethinks methinks bethought methought bets Metz bey may Bicester Mr bidden midden bier mere biers meres bight might bight mite bights mites bike mike bikes mikes bile mile bilk milk bilked milked bilking milking bilks milks billboard millboard bill mill billed milled billing milling bills mills billet millet billionth millionth billionths millionths billionaire millionaire Billy Millie bind mind binding minding binds minds binder minder binders minders bine mine bines mines birth mirth bite might bite mite bites mites bitten mitten biz Ms boar maw boars maws boar more board Maud boast most boat moat boated moated boats moats boater motor boaters motors bob bomb bobbed bombed bobbing bombing bobs bombs bode mode bodes modes Boer mower Boers mowers boil moil boiled moiled boiling moiling boils moils bold mould bolder moulder bole mole boles moles bolt moult bolted moulted bolting moulting bolts moults Bolton molten bone moan boned moaned bones moans boning moaning boo moo booed mooed booing mooing boos moos boob boom boobed boomed boobing booming boobs booms boon moon boons moons boor moor boors moors boorish Moorish boot moot booted mooted booting mooting boots moots booze moos bore maw bores maws bore more bored Maud Boris Maurice born morn born mourn borne morn borne mourn boron moron borrow morrow borrows morrows boss moss bosses mosses bossy mossy bossier mossier bossiest mossiest bottle mottle bottled mottled bottles mottles bottling mottling boulder moulder boulders moulders bough mow boughs mows bound mound bounds mounds bounty Mountie bounties Mounties bourbon merman Bourne morn Bourne mourn bow mo bow mow bows mows bowing mowing Bowburn bowman bowl mole bowls moles bowled mould bowler molar bowlers molars box mocks buck muck bucked mucked bucking mucking bucks mucks Buckie mucky buckle muckle bud mud budded mudded budding mudding buds muds buddy muddy buddies muddies buff muff buffed muffed buffs muffs bug mug bugged mugged bugging mugging bugs mugs bugger mugger buggers muggers buggy muggy built milt bulked mulct bums mums bumps mumps bunch munch bunched munched bunches munches bunching munching bunk monk bunks monks bunny money bunnies monies bur myrrh burr myrrh burke murk bursar mercer bursars mercers burton Merton bury merry bus muss bused mussed buses musses busing mussing bust must busts musts bustard mustard buster muster busters musters bustle muscle bustled muscled bustles muscles bustling muscling but mutt butt mutt butts mutts butter mutter buttered muttered buttering muttering butters mutters button mutton buy my buyer mire buyers mires by my bye my cab cam cabs cams carbine carmine carbines carmines chubby chummy chubbier chummier chubbiest chummiest cobber comma cobbers commas come cub comes cubs crab cram crabbed crammed crabbing cramming crabs crams dab dam dabs dams dab damn dabbed dammed dabbing damming dabs damns dauber dormer daubers dormers debarkation demarcation dibber dimmer doubly dumbly drab drachm drab dram drub drum drubbed drummed drubbing drumming drubs drums dub dumb dubs dumbs dubbing dumbing dubbed dumbed ebb M ebbs M's Feb fem glebe gleam glebes gleams glibber glimmer grab gram grabs grams grabber grammar grabbers grammars hobo homo hoboes homos hub hum hubs hums jab jam jabbed jammed jabbing jamming jabs jams jab jamb jabs jambs jib gym jibs gyms jib Jim lab lam lab lamb labs lambs labour lamer Lib limb Lib Lymm lobe loam nub numb nubs numbs obeys amaze rib rim ribbed rimmed ribbing rimming ribs rims robe roam robes roams robed roamed robing roaming robe Rome rob rhomb robs rhombs rub rum rubber rummer ruby roomy sahib psalm sahibs psalms scrub scrum scrubs scrums shabby shammy slab slam slabs slams stabber stammer stabbers stammers sub some sub sum subs sums subbed summed subbing summing subway someway tabby tammy tabbies tammies tabor tamer tabors tamers tuba tumour tubas tumours tubby tummy tuber tumour tubers tumours
John Higgins, Shaftesbury, April 2016.