The Third Supplement to the Ninth Edition adds terms helpfully defined for the first time or in a new way, such as "deliberate absence", "exogenous infection"; "Kirpan"; "lobster pot principle"; "lorry surfing"; "pocketknife"; "pornographic material"; "pow" and others. At the same time it updates a number of old favourites including "agreed"; "benefits" consequential"; consideration"; "consumer"; "disproportionate" and many others.