A compound adjective is pretty much exactly what it sounds like. It is an adjective made up of two or more words that describe the same noun together. Most of the time, the words that make up a compound adjective are joined by hyphens, and not all the words used to create a compound adjective need to be adjectives themselves. Compound adjectives may be formed by joining adjectives with other adjectives, nouns, pronouns, and so on. Compound adjectives always show up before the noun they modify. You may also hear them referred to as phrasal adjectives or compound modifiers.
One common way of forming a compound adjective is combining two adjectives, such as when describing colors or directions:
Tim roasted a perfect golden-brown marshmallow over the fire.
I think the sleeping bags are on the top-left shelf in the basement.
The wind is blowing from a west-northwest direction.
It’s also not uncommon to see proper names used as proper collective adjectives, in which case hyphens are unnecessary:
Sarah just bought several Ernest Hemingway books.
Some of the old Rocky Mountain trails were extremely dangerous.
The London Symphony Orchestra concert was unforgettable.
Compound adjectives may also be formed by linking various words and different parts of speech together. Technically there is no upper limit to how many words may be joined in creating a compound adjective, so there is plenty of room for creativity.
This out-of-date software could be riddled with security vulnerabilities.
That’s a good-looking new car you’ve got there.
Our boss is a no-nonsense kind of guy.
Jack’s five-year-old niece really loves the color pink.
The elevator has a 1,500-pound wight limit.
Vicky struggled to keep up with the cleaning after adopting two long-haired cats.
Stewart was grateful to be offered a full-time job.
Mom has been dropping tons of not-so-subtle hints about where she wants to eat for Mother’s Day.
The small brick-and-mortar bookstore could no longer hold out against its online competitors.