In Brit slang, muck about means to take your time…kind of just hanging around doing nothing. Basically, wasting time.
Lady Muck, however, is an entirely different meaning. When you call someone a Lady (or Lord Muck), you are actually insulting or pointing out the obvious character flaw. Calling someone Lord/Lady Muck means that they are putting on airs and acting well above their station in life – a bit like wanting to be well bred when, in reality, they’re living in a shabby place. In short, you’re calling them delusional bastards.
There is a Britcom that I could not stand watching, but a friend of mine loved it. So much so she could watch the same episode over and over and over…to the point where I honestly thought I was going to stab her in her sleep. The Britcom was called Keeping Up Appearances. It still airs on PBS and BBC America. That’s like nails on a chalk board to me. She made me so sick of that show…so much so that I could barely stomach looking it up on Wikipedia. That show incites some serious anger in me.