Lacking energy conclude article further on (5)
I believe the answer is:
infra
'on' is the definition.
Both the answer and definition are adverbs. Maybe you can see an association between them that I can't see?
'lacking energy conclude article further' is the wordplay.
'lacking' is a deletion indicator.
'energy' becomes 'e' (physics symbol as in E=mc2).
'conclude' becomes 'infer' (inferring is a kind of concluding).
'article further' becomes 'a' (the indefinite article in English. I am not sure about the 'further' bit.).
'infer' with 'e' taken away is 'infr'.
'infr'+'a'='INFRA'
Can you help me to learn more?
(Other definitions for infra that I've seen before include "-- Dig means degrading" , "Dig is demeaning" , "Below (as prefix)" , "lower down" , "Latin adverb meaning below or further on in book" .)