1. To take in as a part, element, or member.
2. To contain as a secondary or subordinate element.
3. To consider with or place into a group, class, or total: thanked the host for including us.

Synonyms: These verbs mean to take in or contain as part of something larger. Include often implies an incomplete listing: "Through the process of amendment, interpretation and court decision I have finally been included in 'We, the people'" (Barbara C. Jordan).
Comprise usually implies that all of the components are stated: The book comprises 15 chapters.
Comprehend and embrace usually refer to the taking in of subordinate elements: My field of study comprehends several disciplines. This theory embraces many facets of human behavior.
Involve usually suggests inclusion as a logical consequence or necessary condition: "Every argument involves some assumptions" (Brooke F. Westcott).

Usage Note: Some writers insist that include be used only when it is followed by a partial list of the contents of the referent of the subject. Therefore, one may write New England includes Connecticut and Rhode Island, but one must use comprise or consist of to provide full enumeration: New England comprises (not includes) Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, and Maine. This restriction is too strong. Include does not rule out the possibility of a complete listing. Thus the sentence The bibliography should include all the journal articles you have used does not entail that the bibliography must contain something other than journal articles, though it does leave that possibility open. The use of comprise or consist of, however, will avoid ambiguity when a listing is meant to be exhaustive. Thus the sentence The task force includes all of the Navy units on active duty in the region allows for the possibility that Marine and Army units are also taking part, where the same sentence with comprise would entail that the task force contained only Navy forces. See Usage Note at comprise.