suyo
/ˈsuʝo/ · A2 · pron
his, hers, its
su (his/her/their) + -yo ending, like mío and tuyo: the stand-alone form
From Latin suus, meaning his/her/its own. Su goes before a noun (su libro); suyo stands alone or follows it (el libro es suyo). It rhymes with tuyo, so the set mío, tuyo, suyo runs mine, yours, his/hers/theirs.