c. 1600, "pertaining to possession by a deity," from Greek enthousiastikos "inspired," from enthousiazein "be possessed or inspired by a god" (see enthusiasm). Meaning "pertaining to irrational delusion in religion" is from 1690s. The main modern sense, in reference to feelings or persons, "intensely eager, rapturous," is from 1786. Related: Enthusiastically.
late 14c, in astrology, "position of a planet in the zodiac where it exerts its greatest influence," from Old French exaltacion "enhancement, elevation," and directly from Late Latin exaltationem (nominative exaltatio) "elevation, pride," noun of action from past-participle stem of exaltare "to raise, elevate" (see exalt).
From late 15c. as "act of raising high or state of being elevated" (in power, rank, dignity, etc.); also "elevation of feeling, state of mind involving rapturous emotions." The Exaltation of the Cross (late 14c.) is the feast commemorating the miraculous apparition seen by Constantine in 317.