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:
beckon reckon
bevel revel
bowman Roman
stability sterility
The mean density value is 2.4%. The list makes 186 semantic distinctions, a loading of 48%.
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