The phrase "on tenterhooks" refers to a state of anxiety or tension. To find antonyms for this phrase, we must look for words that represent calmness and relaxation. Some suitable antonyms include "at ease," "carefree," "composed," "relaxed," "serene," and "unworried." When someone is at ease, they are in a state of comfort and have no worries. A carefree person has no concerns or problems. A composed person is calm and collected under pressure, while a relaxed person is devoid of tension or stress. A serene person is entirely peaceful, and an unworried person is free from worries or anxiety. By using antonyms for "on tenterhooks," we can describe someone who is calm, collected, and at peace.