I. noun 1. a member of the lowest order of the British nobility. Baron is not used as a form of address, barons usually being referred to as ‘Lord’. 2. a member of a foreign nobility having a rank similar to that of a British baron. 3.
‹historical› a person who held lands or property from the sovereign or a powerful overlord.
4. [with modifier] — an important or powerful person in a specified business or industry • a press baron.
– origin Middle English: from Old French, from medieval Latin baro, baron- ‘man, warrior’, probably of Germanic origin.