Ward et. al define the evection resonance of the Moon with the Earth and Sun as:
occurring when the lunar perigee precession period equals one year.
Does this simply mean that the angle formed by the Sun-Earth-Moon when the Moon was at perigee was the same every month?
I tried looking at the wikipedia definition of Evection but just found it more confusing.
If it helps, I am curious about the lunar evection resonance because it is often cited as a mechanism to explain Moon/Earth angular momentum shedding necessary if one assumes the Giant Impact Hypothesis of Moon formation. See Ward and Canup:
The resonance can exchange angular momentum between the Earth-Moon system and the Earth's orbit.