What is a Hybrid Angle?

Question

I'm looking at the Wikipedia content surrounding the calculating the position of the sun relative to the earth, and I came across the term "hybrid angle." (Emphasis added.)

Mean longitude is the ecliptic longitude at which an orbiting body could be found if its orbit were circular and free of perturbations. While nominally a simple longitude, in practice the mean longitude is a hybrid angle.

-- Wikipedia entry for Mean Longitude

Is "hybrid angle" a mathematical term, or does it simply mean an angle calculated with some variable adjustment to its input?

Answer 1

I edited the article to remove "hybrid angle", which seems overly vague. It now reads

While nominally a simple longitude, in practice the mean longitude does not correspond to any one physical angle.

Later on there is a comment:

Mean longitude, like mean anomaly, does not measure an angle between any physical objects. It is simply a convenient uniform measure of how far around its orbit a body has progressed since passing the reference direction.

The mean longitude is defined as a sum of three physical angles – longitude of the ascending node, argument of the pericentre, mean anomaly – and the former "hybrid" designation stemmed from this sum.