Lungo
An espresso pulled with more water for longer, giving a larger, milder drink.
A lungo (Italian for "long") is made with the same amount of coffee as an espresso but with considerably more water. Extraction takes longer and the drink is larger and less concentrated.
Because of the longer flow time, more compounds dissolve, including bitter ones, so a lungo can taste harsher. It is not the same as an espresso diluted with water, and it resembles an americano only partly in the result.