Learned about character in part of history (5,3)
I believe the answer is:
stone age
'part of history' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'learned about character' is the wordplay.
'learned' becomes 'sage' (both can mean wise).
'about' indicates putting letters inside.
'character' becomes 'tone' (tone can mean a character or mood).
'sage' going around 'tone' is 'STONE-AGE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for stone age that I've seen before include "before copper came in" , "Neolithic" , "25 [ERA]" , "Go, senate to ancient era before metal was discovered" , "Early period" .)