late 14c., "the body of principles, dogmas, etc., in a religion or field of knowledge," from Old French doctrine (12c.) "teaching, doctrine" and directly from Latin doctrina "a teaching, body of teachings, learning," from doctor "teacher" (see doctor (n.)) + -ina, fem. of -inus, suffix forming fem. abstract nouns (see -ine (1)).
The notion is "whatever is taught or laid down as true by a master or instructor," hence "any set of principles held as true." In Middle English, it could be used generally for "learning, instruction, education." In U.S. history, the Monroe doctrine was put forward in a message to Congress Dec. 2, 1823; the exact phrase is attested by 1848.
"pertaining to doctrine or doctrines, dealing with precepts of conduct," mid-15c., from Old French doctrinal and directly from Late Latin doctrinalis, from doctrina "teaching, body of teachings, learning" (see doctrine).
"one who theorizes without sufficient regard to practical considerations; one who explains things by one narrow set of theories, disregarding all other forces at work," 1820, from French doctrinaire "impractical person," originally "adherent of doctrines" (14c.), from Latin doctrina "teaching, body of teachings, learning" (see doctrine).
At first used in the context of French politics, the French word having been contemptuously applied by rival factions to those who tried to reconcile liberty with royal authority after 1815. Hence, anyone who applies doctrine without making allowance for practical considerations (1831). As an adjective, "characteristic of an impractical theorist, insisting upon the exclusive importance of one narrow theory," from 1834. Related: Doctrinairism.
It forms all or part of: condign; dainty; decent; decor; decorate; decorous; deign; dignify; dignity; diplodocus; disciple; discipline; disdain; docent; Docetism; docile; docimacy; doctor; doctrine; document; dogma; dogmatic; doxology; heterodox; indignance; indignant; indignation; indignity; orthodox; paradox; synecdoche.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit daśasyati "shows honor, is gracious," dacati "makes offerings, bestows;" Greek dokein "to appear, seem, think," dekhesthai "to accept;" Latin decere "to be fitting or suitable," docere "to teach," decus "grace, ornament."