sharp practice (countable and uncountable, plural sharp practices)

1. Commercial activity that is possibly dishonest while not actually being illegal.

   The typical political sharp practice of manipulating history to suit the current agenda.

   • 1946 May and June, J. G. Holmes, “The North Woolwich Branch”, in Railway Magazine, page 174:

     This action was later regarded by some as a piece of rather sharp practice, but Bidder claimed that the landowners concerned […] refused to sell the ground for the railway unless the whole of their property was purchased at a suitable profit to themselves.

   • 2007 August 29, letters to the editor, “More reports from the check-in desk”, in The Guardian,

     If this is not actually illegal, it certainly appears to be a sharp practice.

2. (law) A lawyer's unfairly taking advantage of an opposing party's missteps or inexperience to gain an advantage.

• bad faith