Fatness - Vine's Expository Dictionary of New Testament Words

Fatness

[ 1,,G4096, piotes ]
from pion, fat," from a root, pi---, signifying "swelling," is used metaphorically in Romans 11:17. The gentile believer had become a sharer in the spiritual life and blessing bestowed by Divine covenant upon Abraham and his descendants as set forth under the figure of "the root of (not 'and') the fatness of the olive tree."

Vine's Expository Dictionary of New Testament Words