Here's a clue I saw in an Acorn User crossword in the early 90s, which I've always remembered. It's a long way short of perfect, but still, I liked it... Yalp? (8)
Like this? (4-11) [rab] well, yes, I was aware that was a flaw; I was hoping to get away with a loose sense of ultimate = end. And I want yours to be DEFINITION, but I can't figure out why.