Comprised of is an expression in English that means "composed of". This is thought by language purists to be improper because to "comprise" can already mean to "be composed of", and by that definition, "comprised of" would be ungrammatical. However, another widely accepted definition of to "comprise" is to "compose", hence the commonly accepted meaning of "comprised of" as "composed of".
Accepted uses: "A book comprises multiple chapters," along with, "Multiple chapters compose a book," and, "A book is composed of multiple chapters."
Established but disputed uses: "A book is comprised of multiple chapters," and, "Multiple chapters comprise a book."
The subtle difference between uses in "the whole which is made up by the parts" and "the parts which make up the whole" has led to acquiescence among many language professionals who now accept the phrases "comprised of" and "composed of" as equivalent.
The Cambridge Advanced Learner's Dictionary, Collins English Dictionary and the Oxford Dictionaries regard the form comprised of as standard English usage. This is predicated on its widespread use in both writing and speech.
Despite this, there continues to be resistance to accepting the phrase "comprised of". In 2015, media outlets reported on one Wikipedia editor's efforts to expunge the phrase from any and all articles on the online encyclopedia.
Use
The phrase comprised of has been in use in its current meaning since the early 18th century, and has been used by major novelists, intellectuals and essayists.
Some examples (emphasis added): "For so tho' a Triangle in the most simple and precise Conception of it be only a Figure comprised of three right Lines, yet these three Lines will necessarily make three Angles, and these three Angles will be equal to two right ones, &c." (1704) "Not Punch, nor salmagundi, nor any other Drink or Meat, of more repugnant Compounds, can be comprised of more contrary Ingredients, nor work more different Effects in the various Minds of Men and Women, than that sublime! groveling! joyful! melancholy! flourishing! ruinous! happy! distracting! whimsical, and unaccountable, tame, mad Monster, Love!" (1752) "The supper having been removed, and nothing but the dessert, which is comprised of the choicest fruits, and confectionery in all its various forms and claſſes remaining, the party stand prepared for the attack ..." (1818) "So the younger division of the party, comprised of Nellie Cahill and Edith Paulton, fell to the rear, and the other division kept the front." (1886) "I started another sketch on the strength of this statement, but feeling a bit dubious over his assertion that the one tree was comprised of a whole row, I tackled the 'oldest inhabitant,' an ancient and pensioned park-keeper, who luckily hove in sight." (1902) "The body-covering of birds is, without exception, comprised of feathers, and by this character alone birds may be distinguished from all other animals." (1911) "The mining towns are comprised of the sudden erections which sprung from the finding of gold in the neighbourhood, and are generally surrounded by thick forest." Anthony Trollope, 1873 "One element of the immediate feelings of the concrescent subject is comprised of the anticipatory feelings of the transcendent future in its relation to the immediate fact." Alfred North Whitehead 1929 "There is a dead nerveless area on the Left, comprised of the old sense of paralysis before the horror of the gas chamber." Norman Mailer, 1968 ”The dualism to which Sartre refers is that of the unconscious id, which is wholly comprised of the instinctual drives, and the conscious ego.” Lionel Trilling, 1972 ”The book is comprised of a few of the innumerable letters, statements, speeches and articles delivered by me since 1963.” Bertrand Russell, 1967 ”’The Auroras of Autumn’ is comprised of ten sections, each of unrhymed tercets.” Harold Bloom, 2003 "I never set out to 'write' a memoir — the book called 'A Widow’s Story' is comprised of journal entries from Feb. 11, 2008, through Aug. 29, 2008." Joyce Carol Oates, 2011 ”The House of the Spirits is, or rather retrospectively it became, the last of a trilogy that is comprised of itself, preceded by Daughter of Fortune and Portrait in Sepia.” Christopher Hitchens, 2011
Among more recent examples, the Merriam Webster Dictionary attributes "about 8 percent of our military forces are comprised of women" to former US President Jimmy Carter. The phrase has also been used in several newspapers, including The Washington Post, The New Yorker, The Atlantic and The New York Times.