"End num" is not a widely known term in the English language, and a search of various English dictionaries did not yield any results. However, if we assume that "end num" refers to the concept of an ending or finale, then some antonyms (opposite words) for this term could include "beginning," "starting," "commencement," "introduction," "opening," and "genesis." Other antonyms could include "continuation," "perpetuation," "extension," "prolongation," and "unending." The appropriate antonym would depend on the context in which the word "end num" is being used, and an understanding of similar terms that are commonly used in English would be helpful for clarification.