Sentence:  It was an old, withered man, who had served the Government in the days of the Mutiny as a native officer in a newly raised cavalry <WSD>regiment</WSD>. 
Meaning of the word marked with <WSD> tags:  A unit of armed troops under the command of an officer, and consisting of several smaller units; now specifically, usually composed of two or more battalions. (from 16th c.)