Duck Duck Go is an intriguing new search engine. It’s not special enough to add to The Best Search Engines For ESL/EFL Learners — 2008, but it does have a useful feature.
Its “trick” is that when you type in a query, the first result is a simple one sentence explanation of the term. For example, when I typed in “gladiator” the first thing that popped-up was “was a fighter in ancient Rome” with a link for additional information.
It’s sort of like a combination dictionary/encyclopedia with a very accessible interface.