The spelling of /b/ is always <b> or <bb>. The /r/ sound is <r>, <rr> or <wr>, as well as <rh> in rheum. The homographs bow and row make pairs with each other as well as with other words. Notice how the partial homograph reading/Reading makes pairs with beading and bedding.
The contrast is between a plosive and a continuant, both voiced but widely separated in the mouth. Confusions are not likely.
The pair bugger/rugger surfaces sometimes as an insulting term for rugby players: "rugger buggers". Two other mildly taboo word pairs are bollocks/rowlocks and bum/rum.
Interesting pairs include:
The mean density value is 2.4%. The list makes 186 semantic distinctions, a loading of 48%.
Abo arrow Abos arrows abound around B re baa rah babble rabble babbles rabbles back rack backed racked backing racking backs racks baffle raffle baffled raffled baffles raffles baffling raffling bag rag bagged ragged bagging ragging bags rags bail rail bailed railed bailing railing bails rails bait rate baited rated baiting rating baits rates bake rake baked raked bakes rakes baking raking bale rail baled railed baling railing bales rails bally rally band rand bands rands bandy randy bandier randier bandiest randiest bane rain bane reign bane rein bangle wrangle bangles wrangles bank rank banked ranked banking ranking banks ranks banker rancour banker ranker bankers rankers banned rand bant rant banted ranted banting ranting bants rants banter ranter banters ranters bar rah bare rare barely rarely bareness rareness barer rarer barest rarest baring raring base race based raced basing racing bases races baser racer basest racist bash rash bashes rashes Basil razzle bass race basses races bat rat batted ratted batting ratting bats rats batch ratch batches ratches bate rate bated rated bating rating bates rates batter ratter batters ratters battle rattle battled rattled battles rattles battling rattling batty ratty bawd roared bay ray bays rays bays raise bayed raid be re bead read beading reading beads reads bead reed beads reeds beady reedy beak reek beaks reeks beam ream beams reams beams Rheims bear rare beard reared beater Rita beau roe beaux roes beaux rose beck wreck beckon reckon beckoned reckoned beckoning reckoning beckons reckons beck wreck becks wrecks becks Rex bed read bed red beds reds bedding Reading bee re beef reef beeves reeves beep reap beeps reaps beer rear beers rears belated related belay relay belayed relayed belaying relaying belays relays belie rely belied relied belies relies belying relying belief relief beliefs reliefs believe relieve believed relieved believes relieves believing relieving ben wren bens wrens bench wrench benches wrenches bend rend bending rending bends rends bent rent bents rents bequest request bequests requests best rest bested rested besting resting bests rests beta Rita bevel revel bevelled revelled bevelling revelling bevels revels bey ray beys rays beys raise bib rib bibbed ribbed bibbing ribbing bibs ribs bid rid bids rids bidden ridden biding ridding bide ride bides rides biding riding bier rear biers rears big rig bigger rigger bight right bights rights bight rite bights rites bight write bights writes bike Reich bikes Reichs bile rile bill rill bills rills bind rind binds rinds bine Rhine bite right biting righting bites rights bite rite bites rites bite write bitten written biting writing bites writes boar roar boars roars board roared boast roast boasted roasted boasting roasting boasts roasts boaster roaster boasters roasters boat rote boat wrote boater rota boaters rotas boater rotor boaters rotors bob rob bobbed robbed bobbing robbing bobs robs bobbin robin bobbins robins bode road bodes roads Boer rower Boers rowers bold rolled bole rôle boles rôles bole roll boles rolls bollock rowlock bollocks rowlocks bomb rhomb bombs rhombs bone roan bones roans Bonn Ron bonny Ronnie boo rue boos rues booing ruing booed rued boos ruse booed rude booby ruby boobies rubies book rook booked rooked booking rooking books rooks bookie rookie bookies rookies boom rheum boom room boomed roomed booming rooming booms rooms boon rune boons runes boost roost boosted roosted boosting roosting boosts roosts booster rooster boosters roosters boot root booted rooted booting rooting boots roots boot route boots routes booting routing booted routed Bootle rootle booze ruse bore raw bore roar boring roaring bored roared bores roars bough row boughs rows boughs rouse bought wrought bound round bounded rounded bounding rounding bounds rounds bounder rounder bounders rounders bout rout bouts routs bow roe bows roes bow row bowed rowed bowing rowing bows rows bowed road bows rose bows rouse bowel rowel bowels rowels bowl rôle bowls rôles bowl roll bowls rolls bowling rolling bowled rolled bowler roller bowlers rollers bowman Roman box rocks boy Roy bubble rubble buck ruck bucked rucked bucking rucking bucks rucks buddy ruddy buff rough buffed roughed buffing roughing buffs roughs buffer rougher bug rug bugs rugs bugger rugger bum rum bump rump bumps rumps bunny runny bust rust busted rusted busting rusting busts rusts bustle rustle bustled rustled bustles rustles bustling rustling busty rusty but rut butt rut butted rutted butting rutting butts ruts buy rye buy wry buyer wrier buys rise by rye by wry bye rye bye wry cabbage carriage cabbages carriages cabby carry cabbies carries disobey disarray disobeyed disarrayed disobeying disarraying disobeys disarrays hubby hurry hubbies hurries lobby lorry lobbies lorries obey array obeyed arrayed obeying arraying obeys arrays rose-bed rose-red stability sterility tabby tarry tabbies tarries
John Higgins, Shaftesbury, January 2010.