For each or by means of (3)
I believe the answer is:
per
I believe this is a double definition.
'for each' is the first definition.
(per person)
'by means of' is the second definition.
(I've seen this before)
(Other definitions for per that I've seen before include "Preposition indicating by means of" , "For each or every" , "According to" , "Preposition meaning for each" .)