Gutter
Ditch
noun
The kanji and the word are exactly the same. That means they share meanings as well.
溝 is commonly used for physical gaps like drainage ditches, small trenches, or grooves in surfaces. It can also describe metaphorical gaps, like emotional or relational divides between people.
Since this word is made up of a single kanji, it probably uses the kun'yomi reading. You did not learn this reading, so here's a mnemonic to help you:
If you step in that gutter you'll catch measles (みぞ). A gutter or ditch has all kinds of dirt and germs in it, including measles, so don't go stepping in it or drinking from it!
コインパーキングの横の溝に、万札が落ちてるのを見つけたんだよ。
I found a 10,000 yen bill in a ditch beside a coin operated parking space.