: to think about something : to give your attention to the thing you are doing, reading, etc.
: to cause (attention, efforts, strength, etc.) to be used or directed for a single purpose
: to make (something, such as a liquid) stronger by removing water
: a substance that is made stronger or more pure by removing water
What made you want to look up concentrate? Please tell us where you read or heard it (including the quote, if possible).