adverb. Midway between the bow and the stern.

In or toward the middle of a ship, or that part which is midway between the stem and the stern.

In the middle line of a ship; over and in line with the keel: as, to put the helm amid ships.

adverb. In the middle of a ship, with regard to her length, and sometimes also her breadth.

adverb. In the middle of a ship, either longitudinally or laterally.

adverb. Usually in the line of the keel, but sometimes halfway between bow and stern; often contracted to “midships.” (FM 55-501).

adverb. On the flank, at a vulnerable place.

interjection. A helm order, normally shortened to midships!, to centre the helm in the line of the keel.

adverb. at or near or toward the center of a ship

"The sides of the ships are protected by iron plating of eight-inch thickness amidships, which is an inch more of iron than the armour possessed by the majority of our masted sea-going ironclads, many of which are twice or thrice the size of the _Cyclops_ and her sister-ships."

average  betwixt and between  central  core  equatorial