The word vociferous functions as an adjective and it is used to describe loud, vocal and clamorous speech. In many contexts, vociferous would be a negative, or a pejorative word, but it may also be used in a more positive light, to describe a passionate speech or defence. Linguists and historians trace the roots of the word “vociferous” to the early 17th century and to the Latin language. According to most sources, the term was first used in around 1605, although rather than saying vociferous, it was more common to use the term “vociferant,” when describing someone who was loud, insistent or belligerent. One way to use this word in a sentence is to say that President Barack Obama vociferously rejected Republican accusations during the 2008 election campaign.