This pioneering monographic dictionary documents Spanish loanwords in American slang, a vibrant and expanding part of informal lexicon of American English. The dictionary describes over 500 such expressions, including both those used by Latin Americans and those known to larger segments of American society. Each entry contains the headword, grammatical identification, usage label, definition or equivalent in standard English, bibliographical references, contextual examples of usage with sources and dates, as well as etymological information and dating. The lexical material comes from a large database of citations from various sources such as conversation, film, literature, press, television and the Internet, collected during several research trips to the United States. The dictionary will be useful to students of sociolinguistics and ethnolinguistics, as well as to everyone interested in lexical variation in contemporary American English.