This is another dynamic Bonus Goal, as indicated by the green arrows symbol, meaning that the goal changes over the course of the level. You must make a word that starts with the first indicated letter, and ends with the second indicated letter... in the example above, your word should start with "C" and end with "L" as in COOL or CORRAL.
Once you submit a word with the correct start and end letters, the goal will change to a new pair of letters.
You must do that a certain number of times to achieve the Bonus Goal. In the example above, you must submit 4 matching words.