Vocabulary was the collection of words which made up a language. The vocabulary was often collected in a dictionary. When Hoshi Sato tried to communicate in the Axanar language in 2151, she told Jonathan Archer she'd be lucky if she got half the vocabulary right. (ENT: "Fight or Flight") When Vanna and Captain Kirk reached an agreement over zenite in 2269, Plasus angrily commented there was no such word as "agreed" in the Troglyte vocabulary. (TOS: "The Cloud Minders" )