0 a person born during the period 21 January to 19 February, who is believed to be influenced by the zodiac sign Aquarius:
He's an Aquarian.
My niece Kate and I are both Aquarians.
1 belonging or relating to the zodiac sign Aquarius (= the sign for people born from 21 January to 19 February):
True Aquarians are said to be friendly, creative, optimistic, and fond of science and literature.
We're both Aquarians and dreamers.
Planning isn't really an Aquarian thing.