to cap/crown/top it all
something that you say when you want to tell someone the worst event in a series of bad events that has happened to you He spilled red wine on the carpet, insulted my mother, and to cap it all, broke my favourite vase.
See be all sweetness and light, for all cares, for all knows, That's all she wrote!, be all in a day's work, I've never [felt etc.] in all my days!, be all ears, if all else fails, all eyes are on, be all eyes, be all fur coat and no knickers, It's all go, All in good time, It's all Greek to me, be all heart, at all hours, at all hours, to all intents and purposes, and all that jazz, be all in the/ mind, in all modesty, be all moonlight and roses, be all mouth, in all but name, That's all need!, be all smiles, all systems go, be all talk, would for all the tea in China, be all things to all men, be all fingers and thumbs, go all the way, be all wet, All work and no playto cap it all
if you have been describing bad things which happened and then say that to cap it all something else happened, you mean that the final thing was even worse He spilled red wine on the carpet, insulted my mother, and, to cap it all, he broke my favourite vase.
See to cap it all, If the cap fits, come cap in hand