M.E., from M.Fr. fertil, from L. fertilis "bearing in abundance, fruitful, productive," from ferre "to bear," from PIE root *bher- "to carry," also "to bear children," cognate with Pers. bordan "to carry, bear," → refer.
Bârvar, literally "fruitful," from bâr "fruit; flower; load; charge" + possession suffix -var, related to bordan "to bear, carry," as above.
Fr.: isotope fertile
An → isotope not itself → fissile but that is converted into a fissile isotope, either directly or after a short → decay process following absorption of a → neutron. Example: U-238 can capture a neutron to give U-239. U-239 then decays to Np-239 which in turn decays to fissile Pu-239. The most important fertile isotope is U-238. This is by far the most abundant isotope of natural uranium, making up 99.28%. The important transformation chain is: 92U238 + 0n1→ 93Np239 + β- (23.5 minutes) → 94Pu239 + β- (2.36 days).