IPA: /əˈmɪdʃɪp/
KK: /əˈmɪdˌʃɪp/
In the center part of a ship, between the front and the back.
The crew gathered amidship to discuss the upcoming voyage.
Amidship is formed from "amid" (from Old English "on mid", meaning in the middle) and "ship" (from Old English "scip", meaning a vessel or boat). The term refers to the middle part of a ship.
Think of being 'in the middle' ('amid') of a 'ship' — that's why amidship refers to the central area of a vessel.