How do new words become established in a speech community? This dissertation documents linguistic, cognitive, and social factors that are hypothesized to affect lexical entrenchment, the extent to which a new word becomes part of the lexicon of a speech community. First, in a longitudinal corpus study, I find that linguistic properties such as the range of a word's meaning and the donor language of a borrowing affect lexical entrenchment. Contextual factors such as frequency, dispersion, and a borrowing's cultural context also play a role in lexical entrenchment. Second, a psycholinguistic study examines the extent to which speakers remember previously unseen words. Through eye-tracking, lexical decision, and free recall tasks, I determine that, again, linguistic and contextual information plays a role in the memorability of a new word. Speakers are more likely to remember words used in particular contexts, and they are also more likely to remember certain word types than others. In a third study, I find that musical preferences, knowledge of popular culture, and social ties influence comprehension of African-American English vocabulary. Together, these studies suggest that lexical entrenchment is predictable to an extent previously undocumented. Results indicate that information relating to dynamical, non-linear systems could be profitable in further studies on lexical entrenchment.