tranquilise Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition verb. to make calm or peaceful. Example Sentence They had to tranquilise the animal to capture it. British spelling. More Example Sentences He used a soft voice to tranquilise the dog. Synonyms calm; soothe; pacify Antonyms agitate; disturb; upset Hear It! Say It! Write It! tranquilise Switch to cursive Start Share with your friends: