kind

First recorded before 900; Middle English kind(e) “natural, well-disposed,” Old English gecynde “natural;” see origin at genial¹, kind²

1. Kind, gracious, kindhearted, kindly imply a sympathetic attitude toward others, and a willingness to do good or give pleasure. Kind implies a deep-seated characteristic shown either habitually or on occasion by considerate behavior: a kind father. Gracious often refers to kindness from a superior or older person to a subordinate, an inferior, a child, etc.: a gracious monarch. Kindhearted implies an emotionally sympathetic nature, sometimes easily imposed upon: a kindhearted old woman. Kindly, a mild word, refers usually to general disposition, appearance, manner, etc.: a kindly face.

First recorded before 900; Middle English kinde, Old English gecynd “nature, race, origin”; cognate with Old Norse kyndi, Old High German kikunt, Latin gēns (genitive gentis ); see kin

The phrase these (or those ) kind of, followed by a plural noun ( these kind of flowers; those kind of shoes ) is frequently condemned as ungrammatical because it is said to combine a plural demonstrative ( these; those ) with a singular noun, kind. Historically, kind is an unchanged or unmarked plural noun like deer, folk, sheep, and swine, and the construction these kind of is an old one, occurring in the writings of Shakespeare, Swift, Jane Austen, and, in modern times, Jimmy Carter and Winston Churchill. Kind has also developed the plural kinds, evidently because of the feeling that the old pattern was incorrect. These kind of nevertheless persists in use, especially in less formal speech and writing. In edited, more formal prose, this kind of and these kinds of are more common. Sort of has been influenced by the use of kind as an unchanged plural: these sort of books. This construction too is often considered incorrect and appears mainly in less formal speech and writing.
Kind (or sort ) of as an adverbial modifier meaning “somewhat” occurs in informal speech and writing: Sales have been kind (or sort ) of slow these last few weeks.