Hink-Pink is a game in which player guess a pair of rhythmic words. e.g Ocean-Lotion, Funny-Money
black crack
A crevice is smaller than a cave. I would go with "black crack."
Yes, a hink pink for "dark crevice" could be "gloomy groove." Both phrases feature a dark or shadowy description followed by a similar sounding word with a different meaning.
Lunch punch! :) These hink pinks are HARD!
http://www.makeuptalk.com/forums/t13127/hink-pinks-hinky-pinkys-hinkity-pinkitys-5-13127.html
cow plow
bear tear
maize craze
ham jam
neat feat
last blast
flower shower