When something is particular, it's specific rather than general. If your teacher asks for a particular book, she means one exact book, not just any book from the shelf. When you're looking for a particular LEGO piece to finish your model, you need that precise shape and color, not just something similar.

The word also describes someone who cares deeply about details and has high standards. A chef who's particular about ingredients won't accept wilted herbs or stale spices. An architect who's particular about measurements checks every dimension twice. When someone says “I'm not particular,” they mean they're flexible and easy to please: any flavor of ice cream works fine, any seat at the movie theater is okay.

Being particular can be valuable. A surgeon needs to be extremely particular about sterilizing instruments. A detective must notice particular details that others miss. But taken too far, being overly particular can make someone seem fussy or impossible to satisfy, like a friend who complains that their sandwich bread isn't sliced to exactly the right thickness.

You might hear the phrase in particular, which means especially or specifically: “I love all subjects, but I enjoy science in particular.”