booty - 'boot-ay' - (noun)

Copied from an email response to Mr Andrew-

The proper booty, you see, or 'bootay' if you will has just the ratio between muscle and cushion. Enough muscle is important in that that it is firm and juicy, yet just enough cushion all the same that there is a bit of feminine 'give' (sometimes known as more cushion for the pushin'), or jelly, for a sexy jiggle. But! One must be careful that there is not too much on the cushion side of the ratio, as we all know what that leads to; both aspects, of course, also contribute to the keystone of the matter, shapeliness. Thus, we have the perfectly smackable, grab-able, push-able (as it were) booty. One might note as a postscript that it doesn't matter whether a gal is slender or more curvy, as both can interestingly have that shapely tush.