Definitions for "Brachial plexus"
Network or tangle of nerves originating from the ventral branches of the last four cervical spinal nerves and most of the ventral branch of the first thoracic spinal nerves. It situates partly in the neck and partly in the armpit area.
mixed spinal nerves innervating the upper limb form a complex meshwork (crossing). ( More? Neural Notes)
A complete network of nerves that is formed chiefly by the lower four cervical nerves and the first thoracic nerve and supplies nerves to the chest, shoulder and arm.