You can focus your searches by using the intitle: parameter. Here's how:
(1) In the Wikipedia search box, type the word intitle followed by a colon, then the word or phrase you are looking for. When you click on "Search," then, you'll be presented with a list of articles that have your search term in their titles.
(2) You can also search for one word or phrase in the title and for others in the text of the articles. For example:
Articles containing the exact expression international airport in their titles.
An even more powerful tool for searching titles is Grep. It lets you search titles using regular expressions, and in the results it lists the titles only.