phonetic map : 灰 hui

CSV-list (for the import to Flashcard apps; "@" is delimeter):

咴儿咴儿@huīrhuīr@neigh; whinny
帽盔@màokuī@n. skullcap
恢@huī@extensive / recover
恢伟@huīwěi@vast; immense
恢复@huīfù@to resume; recover
灰@huī@ash; dust / gray / pessimistic
灰心@huīxīn@to lose heart
灰色@huīsè@gray; gloomy
盔@kuī@n. helmet
诙@huī@ridicule
诙谐@huīxié@humorous

The pinyin "hui" is actually pronounced as "huei" or something like that, though ei is not so clear. The same can be said for "dui" and "tui".

note that 灰 is a component of character 炭