Antonyms for the phrase "put at ease" could include "unsettle," "discomfort," "disturb," "perturb," or "agitate." These words convey the opposite meaning of feeling calm and relaxed, instead suggesting a sense of unease or tension. To "unsettle" someone is to make them feel anxious or nervous, while to "discomfort" them is to cause physical or emotional discomfort. "Disturb" and "perturb" both suggest a sense of disquiet or disturbance, while "agitate" implies an even greater degree of anxiety or upset. Overall, the antonyms for "put at ease" convey a sense of discomfort, disturbance, and unrest.