Main definitions of eta in English

1The seventh letter of the Greek alphabet (Η, η), transliterated as ‘e’ or ‘ē’.

1. 1.1Astronomy followed by Latin genitive The seventh star in a constellation.
   ‘Eta Carinae’
   More example sentences

   • ‘This region, about 8000 light-years from Earth, is located near to the famous explosive variable star Eta Carinae, which lies just outside the field of view toward the upper right.’
   • ‘The striking picture reveals an eclectic mix of embryonic stars living in the tattered neighborhood of one of the most famous massive stars in our Milky Way galaxy, Eta Carinae.’
   • ‘Researchers using NASA's Far Ultraviolet Spectroscopic Explorer satellite have made the first ever direct observation of Eta Carinae's companion star.’
   • ‘That galaxy is just a little more than one degree east of Eta Piscium.’
   • ‘On the night of 10 September 1784, the English astronomer Edward Pigott noticed variations in the brightness of Eta Aquilae, a star lying in the constellation Aquila.’

An estimated time of arrival, in particular the time at which an aircraft or ship is expected to arrive at its destination.

A Basque separatist movement in Spain, founded in 1959.

Edited to add (used in online discussions to indicate that one has modified the content of a post one has made, typically in order to add something)