The word "borde" in Spanish can have several synonyms, depending on the context it's being used in. For instance, if "borde" refers to the edge of something, the synonyms could be "orilla" or "margen." If it refers to someone being rude or unpleasant, then "antipático" or "desagradable" could be used. On the other hand, "borde" can also mean someone who is on the verge of doing something, in this case, "al borde de" or "a punto de" are good substitutes. When it comes to the taste, "borde" can be used as an adjective to describe something that is slightly bitter or sour, and "agrio" or "amargo" are good synonyms.