The phrase "did offhand" implies doing something without thinking or planning. Its antonyms, on the other hand, suggest a more deliberate, measured approach. Synonyms for the phrase could include "spontaneously," "impulsively," or "haphazardly." However, antonyms for "did offhand" might include "carefully," "deliberately," "thoughtfully," or "intentionally." When faced with a task or decision, using the opposite of "did offhand" can often be a wise choice, allowing one to approach the situation with more mindfulness and consideration. In contrast, acting "offhand" can lead to mistakes, oversights, and unintended consequences.