The term 'having great beauty and splendour' can be described as RESPLENDENT, which is an 11-letter word. RESPLENDENT is an adjective that means to be dazzlingly bright or magnificent in appearance. It is often used to describe something that is so beautiful that it is almost blinding. The term is often used to describe the beauty of nature, such as a sunset or a rainbow, but can also be used to describe people or objects.