The antonyms for the word "wast derelict" would be "functional", "maintained", "occupied", "inhabited", "cared-for", and "in good condition". These words indicate that a place or object is well-maintained, in use, or inhabited, whereas "derelict" implies a state of abandonment, disrepair, or neglect. The opposite of "waste" could be "preserve" or "conserve", which suggests an effort to protect or maintain resources, rather than letting them go to waste. In general, antonyms for wast and derelict convey a sense of productivity, vitality, and care - the opposite of decay, neglect, and waste.