The Longman dictionary of law - L. B Curzon

For nearly twenty five years, this invaluable reference work has provided a window on the process of continual change which characterises English law. Intended for students and practising legal professionals alike, the 7th edition has been updated with four years of legislative and case law developments.

Entries are substantial and fully referenced, making follow-up in more detailed information sources much easier.
The dictionary also features a companion website which provides useful links to web-based resources of legal information, and updates to existing definitions as well as new ones.