gutter, ditch, sewer, drain, 10**32
溝 centers on a channel that carries water or waste: a gutter, ditch, sewer, or drain. The rare numeric sense 10**32 is a specialized application of the idea of a huge channel or groove.
溝 combines 氵 (water) with 冓, which likely contributes the sound コウ and the idea of a constructed channel or framework. The character originally referred to man-made waterways.
Water 氵 flows through a structured framework 冓, like a gutter or ditch channeling rainwater away.
For コウ, imagine a construction worker shouting 'Go!' as water rushes through a newly built gutter: Go -> コウ, and the water drains away.
ditch; drain; gutter; trench
ditch; drain; gutter; trench
oceanic trench; deep-sea trench; deep
gutter; ditch
brown rat (Rattus norvegicus); common rat; street rat; sewer rat; Norway rat
Marco Polo Bridge (China)
rift valley
L-shaped gutter; L-shaped drain
U-shaped gutter
keyway
Mariana Trench (deepest part of the ocean, near the Mariana Islands)
record groove
Japanese bird cherry (Prunus grayana); Gray's bird cherry; Gray's chokecherry
drainage ditch; canal
mammary slit (in whales, dolphins and porpoises)
multipurpose underground utility conduit
gutter oil; recycled waste oil sold illicitly in China as a cheaper alternative to normal cooking oil
lateral sulcus (brain structure); Sylvian fissure; lateral fissure
large ditch
plant native to eastern Russia and Hokkaido (Mimulus sessilifolius Maxim. p)