The word "heckuva" is an informal term that can be used to express emphasis or admiration. It is often used in American English, and can be replaced by synonyms such as "fantastic", "amazing", "incredible", "awesome", "unbelievable", "remarkable", and "extraordinary". These synonyms can be used to convey the same strong emotion or admiration associated with the word "heckuva". Additionally, depending on the context, other informal expressions, such as "wow" or "holy cow", can be used to express amazement, astonishment, or enthusiasm. Regardless of the term used, the aim is to express a powerful emotion or to convey admiration for someone or something.