Writer is disturbed by book being oddly ignored (5)
I believe the answer is:
ibsen
'writer' is the definition.
(dramatist Henrik Ibsen)
'is disturbed by book being oddly ignored' is the wordplay.
'disturbed by' means one lot of letters goes inside another (inserted letters disrupt or disturb the word).
'book' becomes 'b' (abbreviation for book).
'oddly ignored' means one should take alternating letters (letters in odd-numbered positions are removed).
The alternate letters of 'being' are 'en'.
'is' placed around 'b' is 'ibs'.
'ibs'+'en'='IBSEN'
(Other definitions for ibsen that I've seen before include "Norwegian dramatist and poet" , "Norwegian author of 'Peer Gynt' etc" , "Norwegian playwright, d. 1906" , "Norse playwright" , "Norwegian playwright (Peer Gynt)" .)