in reference to the epoch that began 10,000 years ago and continues today, 1897, from French holocène (1867), from Greek holos "whole" (from PIE root *sol- "whole, well-kept") + -cene. The notion is "entirely new."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit sarvah "uninjured, intact, whole;" Avestan haurva- "uninjured, intact;" Old Persian haruva-; Greek holos "whole;" Latin salvus "uninjured, in good health, safe," salus "good health," solidus "solid;" Armenian olj "whole, healthy."
word-forming element in geology to indicate more recent periods, introduced by Sir Charles Lyell (1797-1875), from Latinized form of Greek kainos "new," cognate with Latin recens (see recent). Also see Cenozoic.
<a href="https://www.etymonline.com/word/Holocene">Etymology of Holocene by etymonline</a>
Harper, D. (n.d.). Etymology of Holocene. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/Holocene