Five percent went into making up tithe (9)
I believe the answer is:
twentieth
'five percent' is the definition.
The answer and definition can be both relationships as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'went into making up tithe' is the wordplay.
I cannot quite see how this works, but
an anagram of 'went' is 'twen' which is located in the answer.
an anagram of 'tithe' is 'tieth' which is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for twentieth that I've seen before include "Ordinal number for this century" , "Last century" , "at the end of a score" .)