IPA: /ˈmɪdˌwɔːtər/
KK: /mɪdˈwɔːtər/
The central area of a body of water, typically where the water is neither at the surface nor at the bottom.
The researchers studied the fish that live in the midwater zone of the ocean.
Midwater → It is formed from "mid-" (meaning middle) and "water" (from Old English "wæter", meaning water). The word "midwater" refers to the middle layer of water in a body of water, such as an ocean or lake.
Think of being in the 'middle' ('mid-') of the 'water' — that's what midwater means.