In Hamlet I.ii, Hamlet describes Claudius, or at least his relationship to Claudius, as being
A little more than kin and less than kind.
This line is so much fun! First, it's a joke on the similarity between the words 'kin' (a relative outside your immediate family of parents, children, and siblings), and 'kind', and on 'kind's double meaning--the way we know it, meaning nice or considerate, and an older meaning, something like 'ancestor' or 'relative'. Claudius, according to Hamlet, is more than a distant relative, because he is now both uncle and stepfather, but he isn't very nice or considerate.
Some literary devices in this line are alliteration between kin and kind, irony (Hamlet speaks in an aside to the audience), and a double entendre.
We learn a lot about both characters from just this one line--Hamlet is clever with words, and he's angry, but more comfortable with insinuation and double entendres than a direct confrontation. Claudius, if we believe Hamlet's take on him, is unkind, a particularly faulty part of his personality when it comes to the way he treats his family, the people he should be kindest to.