Detailed description one put before people, for example (8)
I believe the answer is:
specimen
'example' is the definition.
(specimen is a kind of example)
'detailed description one put before people' is the wordplay.
'detailed description' becomes 'spec' (I've seen this before).
'one' becomes 'i' (Roman numeral).
'put before' means one lot of letters go next to another.
'people' becomes 'men' (man is a kind of person).
'spec'+'i'+'men'='SPECIMEN'
'for' is the link.
(Other definitions for specimen that I've seen before include "blood sample" , "Sample taken for medical testing" , "Copy" , "Person critically" , "Sample to be studied" .)