Antonyms for the phrase "tremble precariously" might include feeling steady, standing firmly, or being planted securely. Other words that might be used as antonyms could include fixed, stable, steady, and secure. In general, the opposite of tremble precariously would be a sense of stability, confidence, and surety. Antonyms might reflect different levels of certainty or steadfastness, such as solid, anchored, or unyielding. Strong antonyms can help create a sense of contrast in a piece of writing, helping to emphasize the importance of stability and the dangers of uncertainty and insecurity.