excrescence n.

word-forming element, in English meaning usually "out of, from," but also "upwards, completely, deprive of, without," and "former;" from Latin ex "out of, from within; from which time, since; according to; in regard to," from PIE *eghs "out" (source also of Gaulish ex-, Old Irish ess-, Old Church Slavonic izu, Russian iz). In some cases also from Greek cognate ex, ek. PIE *eghs had comparative form *eks-tero and superlative *eks-t(e)r-emo-. Often reduced to e- before -b-, -d-, -g-, consonantal -i-, -l-, -m-, -n-, -v- (as in elude, emerge, evaporate, etc.).

Proto-Indo-European root meaning "to grow."

It forms all or part of: accretion; accrue; cereal; Ceres; concrete; create; creation; creature; Creole; crescendo; crescent; crew (n.) "group of soldiers;" croissant; cru; decrease; Dioscuri; excrescence; excrescent; griot; increase; Kore; procerity; procreate; procreation; recreate; recreation; recruit; sincere.

It is the hypothetical source of/evidence for its existence is provided by: Greek kouros "boy," korē "girl;" Latin crescere "come forth, spring up, grow, thrive, swell," Ceres, goddess of agriculture, creare "to bring forth, create, produce;" Armenian serem "bring forth," serim "be born."