Other forms: including, included, includes
If a whole has something inside it, it includes it. The price includes breakfast, the box includes batteries, the squad includes two new players.
Include also means making room for a person: include me in the plans, include her name on the list. Including is the preposition, and it opens a partial list, so five countries, including France and Spain names examples rather than the whole set; if you want the full list, say the five countries are. The opposite is exclude, and the nouns are inclusion and exclusion. Inclusive leads two lives: a price that is inclusive covers everything, while an inclusive school is one where everybody belongs. On bills you meet VAT inclusive and service included.
1verbincludeTo have something as one of its parts.
“The rent includes water and heating.”
2verbinvolveTo make someone or something part of a group, list or activity.
“They included her in the invitation at the last minute.”
Too few real examples of this word to estimate which sense is commonest.
Include comes from Latin inclūdō, "to shut in, enclose", built from in-, "in", and claudo, "to shut", and back beyond that to a Proto-Indo-European root *(s)kleh₂w-, "key, hook, nail". So to include something is to shut it in, from the same root as a key in a lock. Enclose is the same Latin word arriving by another road, and both pushed aside the older English belūcan.
Proto-Indo-European
*(s)kleh₂w- — key, hook, nail
Latin
inclūdō — to shut in, enclose, insert
Middle English
includen
English, today
include
Built from
From Middle English includen, borrowed from Latin inclūdō (“to shut in, enclose, insert”), from in- (“in”) + claudo (“to shut”), ultimately from Proto-Indo-European (s)kleh₂w- (“key, hook, nail”). a doublet of enclose. Displaced native belūcan (“to include,” also “to shut in”).
Etymology from Wiktionary, CC BY-SA