Continuity and Discontinuity in the Transmission of Spanish Inherited Words Competed by Arabisms: oliva and aceituna, olio and aceite, olivo and aceituno. The loss and replacement of Arabisms by Latin loanwords was a frequent phenomenon between the sixteenth and the seventeenth centuries; the opposite movement, the replacement of an inherited word by an Arabism is far less frequent. Oliva, an inherited word, is competed by the Arabism aceituna; currently the common name for the fruit in the Hispanic world is aceituna, and oliva has a restricted use to the phrase aceite de oliva or to refer to a colour. Similarly, the inherited word olio will be replaced by aceite, and with a specialized meaning will be eliminated by the euphuism óleo, its etymological doublet. On the other hand, olivo prevails over aceituno and represents a special case of continuity in this lexical family. The research will be carried out in two directions: first, I will analyse the old academic dictionaries and other specialized dictionaries and glossaries from the fifteenth-twentieth centuries. Second, I will conduct a corpus analysis, based on the diachronic corpora available for the Spanish language. This study will try to answer the questions how? and why? of these neological movements of vocabulary. Keywords: inherited words, Arabisms, oliva, aceituna, lexical substitution