There are several synonyms for the phrase "wast above-board", which means to act honestly and transparently. One synonym could be "above reproach", indicating that one's actions are beyond criticism or suspicion. Another synonym could be "squeaky clean", suggesting that there is nothing to hide and no hidden motives. "Transparent" and "forthright" could also be used, as they convey the idea of acting openly and honestly. In contrast, antonyms of "wast above-board" could include "dishonest", "deceitful", or "sneaky", implying that actions are carried out secretly or with ulterior motives.