Writer pens a point -- elementary (5)
I believe the answer is:
basic
'elementary' is the definition.
('basic' can be similar in meaning to 'elementary')
'writer pens a point' is the wordplay.
'writer' becomes 'bic' (kind of pen).
'pens' is an insertion indicator.
'point' becomes 's' (S is an example).
'a'+'s'='as'
'bic' enclosing 'as' is 'BASIC'.
(Other definitions for basic that I've seen before include "Staple; ordinary" , "Fundamental instruction's" , "Fundamental -- early computer language" , "No-frills" , "At the simplest level" .)