The word that rhymes with "treasure" is "leisure". The two words share the same "zh" sound at the end, which is also known as a voiced palato-alveolar fricative. This sound is made by placing the tongue between the roof of the mouth and the teeth and pushing air through, creating a buzzing or hissing sound. "Vapour" and "texture" have different ending sounds, while "reason" has a different vowel sound at the beginning.