If something is "ordinary," it’s average. There’s isn’t anything unusual or unique about it. This word is similar to typical or normal.
The houses on this block are ordinary. Many of them look alike.
Sarah prefers to wear ordinary clothes to work because she doesn’t want to attract attention to herself.
It was just another ordinary day until Ahmed got a flat tire, and then everything went downhill from there.
Instead of getting an ordinary haircut, he decided to go with a mohawk.
He has a mohawk.That is not an ordinary haircut.
The adverb form of this word is "ordinarily."
Ordinarily, Barb works during the week, but today she’s working on the weekend.
Summer in the United States is ordinarily hot, but last summer was extraordinary. (The opposite of "ordinary" is "extraordinary.")
Doctor Jensen ordinarily works with patients who are children because he works in the pediatric ward.
Note: Be careful when using the word "ordinary." Some people take offense if their clothes, lifestyle, or material possessions are described as being "ordinary." Many people like to believe they are unique–even if they aren’t.