Hello, Christine. The dictionary's definition is not wrong, although incomplete. In fact, "ir" e "vir" are also related to the person and the place that is focused on the sentence. Ex.: "Eu tenho que IR ao escritório mais cedo hoje" - It implies that you are not in the office, yet. However, if you say: "Eu tenho que VIR ao escritório todos os dias neste horário" - In that case, you are already in the office at the moment you said the sentence.. *ps.: Notice that in portuguese we also have the verb "VER" (to see), that also can be conjugated as "vir" in the Future Subjunctive mode. Ex.: "Se você vir esse filme, provavelmente irá adorá-lo." I hope this clarifies the matter.