lake
湖 centers on a large body of fresh water surrounded by land: a lake.
湖 combines 氵 (water) with 胡, which likely provides the sound コ. The character originally referred to a large body of water, and the modern form retains that meaning.
Water 氵 on the left and 胡 on the right: picture a calm lake reflecting the moon 月, with the sound of water lapping at an ancient mouth 口 of a river, all under a cross-shaped 十 constellation.
For コ, imagine a small child (子, こ) playing by the lake, skipping stones across the water: 子 -> コ, and the lake is the perfect place for a child's adventure.
lake
Lake Biwa; Biwako
lakeside; lakeshore; lakefront
lake; lake water
lake surface
lake; marsh; wetland; inland waters
north of a lake; north of Lake Biwa
on the lake
bottom of a lake
underground lake; subterranean lake
lakeshore; lakeside
artificial lake; man-made lake; reservoir
caldera lake
reservoir; lake formed by a dam
oxbow lake; billabong
artificial lake; man-made lake; reservoir
endorheic basin
underground lake; subterranean lake
dammed lake (formed by natural damming of a river, esp. by landslide, volcanic eruption, etc.)
saltwater or saline lake