I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
shadier shader shoddier shudder shatter shedder shuddery shittier chattier chider chadar cheder chadri chador chowder chitter shooter chudder sheeter chatter shouter cheater shutter chattery shoetree cheddar chuddar
headier readier beadier leadier shadier rowdier dowdier muddier sadder ladder meatier header beader bawdier woodier faddier madder deader badder lauder nadir padder raider fader adder wadder baiter kneader waiter ruddier weedier tidier needier seedier lader gaudier reedier aider hoodier deedier gaiter wader reader peatier loader leader moodier gadder matier giddier shader shoddier
shad shade shadow shadowy shady