【Kingly】 , 【regal】 , 【royal】 , 【queenly】 , 【imperial】 , 【princely】 are comparable when meaning of, relating to, or befitting one who occupies a throne.
【Kingly】 , 【regal】 , and 【royal】 are often interchanged, especially when used in reference to a monarch who is called king; thus, 【kingly】 , 【regal】 , or 【royal】 power are equally appropriate and idiomatic. However, usage shows a degree of preference for 【kingly】 when the reference is to the personal or ideal character of a king or to his feelings, disposition, aims, or actions or for 【regal】 when the reference is to the king’s office or the state or pomp which accompanies the exercise of his powers and for 【royal】 when the reference is to persons or things associated with the king either as a person or as a monarch, but not necessarily involving magnificence or display. In extended use 【kingly】 carries the strongest implication of dignity and nobility while 【regal】 suggests magnificence or majestic character and 【royal】 , fitness or suitability for a king especially in superlative excellence.
【Queenly】 is used in place of 【kingly】 when the reference is directly to a person who is a female sovereign in her own right or is the consort of a king. But when the reference is to the office, the family of the queen, or anything to which 【regal】 and 【royal】 are normally applied, the latter adjectives are used without reference to the sex of the sovereign.
【Imperial】 suggests reference to a monarch who is called emperor or empress. In extended use 【imperial】 implies fitness or suitability for an emperor or empress and typically suggests a more awe-inspiring quality than 【kingly】 and more pomp and grandeur than 【regal】 or 【royal】 .
【Princely】 implies reference to one who is called a prince and especially to one who is so called as the monarch of a principality, as the heir to a 【royal】 throne, or as a male member of the immediate 【royal】 family. In its extended use 【princely】 often carries a strong implication of sumptuousness or of opulence or munificence.
