What does acronym SETI stand for?

The Search for Extra-Terrestrial Intelligence (SETI) has been going on for many years, primarily with the Arecibo Radio Telescope in Arecibo, Puerto Rico, which began its participation in the programme back in 1999. The dish is 1000 feet across (305 metres) and is the largest single aperture telescope in the world. It took three and a half years to build, beginning in June 1960.