detach
v.v. to separate something from a larger group or object. In the military, it means to move a unit away from its main group to do a different job.
v. to separate or disengage something from a larger whole or from a specific location. In a military context, it refers to the formal removal of a unit from its parent formation for a specific mission.
The army decided to detach a small group to guard the border.
The general ordered the detachment of the medical unit to provide immediate aid to the injured soldiers.
By detaching the reconnaissance squad from the main column, the commander ensured that the enemy would not be aware of the primary objective until the final phase of the operation began.
From Old French destachier, from the same root as attach; compare French détacher and Portuguese and Spanish destacar.