great diversity of form; myriad forms
A yojijukugo used in literary or formal contexts to describe an immense variety of shapes, appearances, or styles. Rare in everyday speech.
This museum exhibits sculptures of great diversity of form.
千差万別 is more common and means 'an infinite variety of differences', focusing on diversity in general, while 千態万様 specifically emphasizes variety in forms or appearances.
A yojijukugo composed of 千 (thousand), 態 (form/appearance), 万 (ten thousand), and 様 (form/style), literally 'a thousand forms, ten thousand styles'. The exact historical derivation is uncertain, but it follows a common pattern of using large numbers to express abundance.