Also known as ‘decans’; divisions of the signs into 10° sections, each of which is governed by one of the traditional planets. These appear to be based upon the Egyptian division of the year into 36 ten-day periods, each presided over by a particular stellar deity. The 4th century astrologer Firmicus Maternus is among many who placed great emphasis on their use, saying that a planet in its own decan is as good as in its own sign. Like Manilius before him, he attributed decan rulership to the signs of the zodiac, but most authors, including Ptolemy, gave them to the planets in descending order towards the earth, (i.e., Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon). Their order reflects planetary rulership over the days of the week.

See ‘masculine/feminine’.

The signs of the water triplicity: Cancer, Scorpio and Pisces, defined as fruitful because of their moist influence which is conducive to fertility. Unless afflicted, they show (amongst other things) a propensity for large families, many children or easy pregnancy. Scorpio is the least promising in this regard because where it is afflicted it can indicate many pregnancies that fail.

Many traditional authorities claim that a planet within 5 degree of a house cusp should be considered to have its influence within that house. For example, if Mars is at 3° Taurus, and the 2nd house cusp at 7° Taurus, Mars would be considered an essentially ‘3rd house’ planet. 

Taurus, Leo, Scorpio and Aquarius.

See ‘benefic planets’.

Where two significators are applying towards conjunction, but before it perfects the slower planet has already caught up with and perfected a conjunction with another planet. This third planet can interfere with the promise of the contact between the two significators.

In this example, the Sun strains to meet with Mars but is frustrated
because Mars perfects a conjunction with Jupiter first.