Something that's connective connects or attaches things to each other. In grammar, connective words such as "like" or "than" connect clauses or phrases.
A connective device on your computer, like a modem, connects it with the Internet, and connective tissue in your body connects organs, tissues, bones, muscles, and other body parts to each other. Sometimes a connective word or conjunction is also called a connective. The word comes from the verb connect, from the Latin root conectere, "join together."