DEFINITION
When two significators apply by major aspect to each other but before perfecting the
slower of the two, the planet doing the frustrating, aspects a third planet therefore
frustrating the faster significator and leading to a "no" or negative answer to
the question.
Although the three outer planets are never used as main significators, they can be
involved in frustration.
This is the first of two rules where inhibiting planets have the power to prevent major
aspects from perfecting between significators even though they are within the moiety of
their orbs at the time of the question.
Examples
Example 1: Mercury ruler of the ascendant at 8 degrees Sagittarius is applying by
conjunction to Venus ruler of the 2nd house of the quesited at 12 degrees Sagittarius, but
before the aspect is completed, Venus trines Mars at 13 degrees Leo. Mercury is therefore
the frustrated planet.
Example 2: The Moon ruling the ascendant at 2 degrees Aries is applying by square to
Mercury ruler of the 12th house of the quesited at 8 degrees 15 minutes of Cancer, but
before the square is perfected Mercury conjuncts the Sun at 8 degrees 30 minutes of
Cancer. The Moon is the frustrated planet.
Example 3: The Sun ruling the ascendant at 18 degrees Taurus applies to retrograde Mercury
ruler of the 9th house of the quesited at 22 degrees Taurus, but before they perfect their
conjunction Mercury perfects a trine with Jupiter at 21 degrees Virgo.
The Sun is the frustrated planet.Example 3