In astrology, a sextile is an astrological aspect that is made when two planets or other celestial bodies are 60 degrees apart. A sextile is considered to be highly beneficial, being the sixth harmonic (360 / 6 = 60) of the 360 degree zodiac. Because the sextile is the sixth harmonic of the circle, it takes on many of the qualities of the planet Venus, therefore bringing many opportunities to the native.
It is similar to a trine in that it can bring out or accentuate the good characteristics in a suitable subject, although their influence is not quite as strong as a trine. It is one of the moderately powerful aspects.
An example of an aspect would be the Sun in 10 degrees Aquarius forming a sextile to Mars in 10 degrees Aries. In such an instance the native might have a great deal of energy and enthusiasm that he could use to make friends and advance himself.
Historically, Sextile was the ancient name of August, before its name change in honor of Emperor Augustus.