Irish novelist frowning on English (6)
I believe the answer is:
sterne
'irish novelist' is the definition.
(18th-century novelist Laurence Sterne)
'frowning on english' is the wordplay.
'frowning' becomes 'stern'.
'on' says to put letters next to each other.
'english' becomes 'E' (abbreviation).
'stern'+'e'='STERNE'
(Other definitions for sterne that I've seen before include "Irish-born novelist (A Sentimental Journey)" , "Laurence ..., author of 'Tristram Shandy'" , "Author of Tristram Shandy, d. 1768" , "Writer" , "Laurence ...... wrote ` `Tristram Shandy' '" .)