For example, the word "city" connotes the attributes of largeness, populousness. It denotes individual objects such as London, New York, Paris.
It should not to be confused (though it often is) with the distinction between sense and reference, though it has some affinity with his distinction between Concept and Object.
Mill's definition of the term "connotation" is altogether different from that used by Scholastic logicians. In scholastic logic, a "connotative" term was originally what would now be called an adjective, "signifying an attribute as qualifying a subject". For example, "brave", as used to say or imply of some particular person that they are brave. By contrast, the abstract noun "bravery" was thought to signify something independent of the subject, an "independent entity", thus is non-connotative. The distinction is connected with the metaphysical one between substance and attribute.