Gilt-edged securities

Gilts are bonds issued by the governments of the United Kingdom, South Africa, or Ireland. The term is of British origin, and refers to the debt securities issued by the Bank of England, which had a gilt (or gilded) edge. Hence, they are called gilt-edged securities, or gilts for short. Generally, when a market participant refers to gilts, what is meant is British gilts unless otherwise specified, and the description below applies to the UK gilt market.
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British and Irish government securities. Blue Chip 

UK Government bonds or loan stocks. Debt securities or instruments issued by the Government paying, usually, a fixed rate of interest and regarded, because of the Government backing, as the safest form of capital retention. Hence, low risk but also, potentially, low reward.