Adaptive Search is a feature from Bing which produces search results in the context of your previous searches. It's part of Bing's overall search personalisation strategy.
By using the information in your recent search history, Adaptive Search technology aims to gauge the intent behind searches a lot more accurately.
Bing revealed their new Adaptive Search technology in September 2014 when Bing's Stefan Weisz described it in the following way:
"Every time you search on Bing, the information provided helps Bing understand what you're trying to do. The more you search, the more Bing can learn - and use that information to adapt the experience so you can spend less time searching and accomplish what you set out to do."
Adaptive Search is an update to Bing's ongoing personalised search functionality, something which all search engines are eager to perfect. Read more about search personalisation on Bing's blog.
If you search for the term "Casablanca" using Bing with no prior search history, you're most likely to see results for the 1942 classic film. However, if you spend some time searching first for North African resorts and holidays without clearing your search history, the search engine will adapt to what you are trying to find and instead show results for "Casablanca" the Moroccan city."