('chiefly Brit') Her career has been 'on the slide' [='on the decline'] for a couple of years.
You were late this morning. I'll 'let it slide' this time, but don't let it happen again.
His parents are concerned that their son's grades have started to 'slide'. [='worsen']
(..) I had to see my Commanding Officer. Well, "she" didn't come either. I do hope you can come on afterwards. Father Kristof's report on the Chinese mission will be with lantern slides. I'm expected at the Tverskoys'. No doubt. But I'm sure that Princess Betsy can wait for you. (..)2012 Anna Karenina