Synonyms for Internal:

adj.

domestic (adjective)
home, intramural.
intuitive (adjective)
gut.
inward (adjective)
central, core, heart, inland, inner, interior, intestinal, intrinsic, inward, subjective, visceral.
private (adjective)
inward.
within (adjective)
constitutional, domestic, enclosed, gut, home, inner, interior, intimate, intramural, intrinsic, inward, national, private, subjective, visceral.

n.

afghan, african, american, arab, asian, asiatic, australian, Arabism, African-Caribbean. abdominal, analyse, analysis, analyst, analyze, aversion therapy, bodily, consciousness, constitutional, couch, ego, external, foreign, free association, organic, physical, collective unconscious. anatomy, civil, figure, human, person, physically, regional, somatic, body image. edge, indoors, within, Into, inlying. body, extramural, extrinsic, fringe, gut, house, institutional, on the inside, under the banner of something. internal (noun)
domestic, home, in, inner, interior, internecine, intimate, intragroup, intramural, intrinsic, intrinsical, inward, national.
within (noun)
enclosed, external, outer, private.

Other synonyms:

indoors, institutional, inlying. within. fringe, Into. house. Other relevant words:
abdominal, body, civil, constitutional, domestic, enclosed, gut, home, house, in, indoors, internecine, intimate, intragroup, intramural, intrinsical, national, organic, physical, private, within, Into, inlying.

Usage examples for internal

  1. When full, they were under enormous internal pressure of over two thousand pounds per square inch. – The Wailing Octopus by Harold Leland Goodwin
  2. The internal condition of the country was now the point for seriously- minded Englishmen. – The Complete Project Gutenberg Works of George Meredith by George Meredith
  3. Another result of the wars of France and Spain was the frequent internal quarrels at Malta. – Knights of Malta, 1523-1798 by R. Cohen