An "estate" often refers to the assets left behind by a person upon his or her death. The assets may include cash, investments, retirement accounts, business interests, real estate, and life insurance policies. Estates may be subject to estate taxes, depending on the amount of the estate.
A "share repurchase" is a purchase of a company's own shares in the open market. This is usually done when management perceives the shares of that company are undervalued. This is done to reduce the number of shares outstanding.