An Etymological Dictionary of Astronomy and Astrophysics

1. The relative amount of a given → chemical element with respect to other elements.
   

2. The amount of an → isotope relative to other isotopes of the same element in a given sample. → overabundance; → underabundance.

Etymology (EN): M.E., from O.Fr. abundance, from L. abundantia “fullness,” from abundare “to overflow,” from L. → ab- “away” + undare “to surge,” from unda “water, wave.”

Etymology (PE): Farâvâni “abundance,” from farâvân “abundant,” from feré “much, more; increase; priority;”
Mid.Pers. frêh “more, much;” O.Pers. fra- “before, forth;”
Av. frā, fərrā “forth, forward;” PIE base *pro-; cf. L. pro “on behalf of, in place of, before, for;” Gk. pro- “before, in front of.”