Once embroiled with Logie epoch (9)
I believe the answer is:
oligocene
'epoch' is the definition.
(I know that Oligocene is a epoch)
'once embroiled with logie' is the wordplay.
'embroiled with' is an anagram indicator.
'once' mixed up with 'logie' makes 'OLIGOCENE'.
(Other definitions for oligocene that I've seen before include "Insects full of energy, one holds, in" , "Ancient period" , "from an ancient time" , "Period when first primates appeared, ie, Cologne (anag.)" , "age long gone" .)