Black hole consumes Irish writer (4)
I believe the answer is:
biro
'writer' is the definition.
(type of pen, something which writes)
'black hole consumes irish' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'hole' becomes 'O'.
'consumes' indicates putting letters inside.
'irish' becomes 'IR' (abbreviation).
'b'+'o'='bo'
'bo' going around 'ir' is 'BIRO'.
(Other definitions for biro that I've seen before include "writer" , "Laszlo Jozsef -, ballpoint pen inventor" , "Type of ballpoint pen" , "Pocket item" , "Writing implement" .)