Strange article describing invention (5)
I believe the answer is:
alien
'strange' is the definition.
('alien' can be a synonym of 'strange')
'article describing invention' is the wordplay.
'article' becomes 'an' (indefinite article).
'describing' means one lot of letters goes inside another (describe can mean to form the outline of).
'invention' becomes 'lie'.
'an' going around 'lie' is 'ALIEN'.
(Other definitions for alien that I've seen before include "Offensive" , "of foreigners" , "exciting film based in space" , "ET" , "immigrant" .)