"pertaining to the zodiacal sign of Aquarius," 1940 in reference to the astrological Age of Aquarius (see Aquarius + -ian). Earlier, "one who uses water instead of wine at the Eucharist" (1580s).
aquaculture
aqualung
aquamarine
aquanaut
aquarelle
Aquarian
aquarium
Aquarius
aquatic
aquatint
aqueduct