* A specific institution of higher education: This is the most common meaning. A college is a post-secondary educational institution that offers courses and programs leading to degrees or certificates. Colleges can vary greatly in size, focus (e.g., liberal arts, technical), and level of prestige.
* A group of similar things: In a less common usage, "college" can refer to a group of similar things, such as a "college of cardinals" (in the Catholic Church) or a "college of electors" (in some political systems). This meaning emphasizes a group with a shared purpose or function.
* A part of a larger university: Some universities are composed of different colleges, each focusing on a particular subject area (e.g., College of Engineering, College of Arts and Sciences). In this case, "college" is a subunit within a larger institution.
Therefore, the most accurate and common understanding of "college" is a post-secondary educational institution.