Feeble-Minded

From BibleEncyclopedia.Net

fē´b'l-mīn´ded (ὀλιγόψυχος, oligópsuchos):

Only in 1 Thessalonians 5:14 the King James Version, in the sense of “fainthearted,” as in the Revised Version (British and American). In Septuagint it is used as the equivalent of kōshēl, the tottering or feeble-kneed in Isaiah 35:3; Isaiah 54:6; oligopsuchía occurs in Septuagint twice (Exodus 6:9; Psalm 54:7), for “anguish of spirit” and “trouble.” The term refers to weakness of will and vacillation of purpose rather than to idiocy or morbid imbecility.