Writer in time too sly unfortunately (7)
I believe the answer is:
tolstoy
'writer' is the definition.
(I've seen this before)
'time too sly unfortunately' is the wordplay.
'time' becomes 't' (abbreviation).
'unfortunately' is an anagram indicator (a bad or unfortunate spelling).
'too'+'sly'='toosly'
'toosly' anagrammed gives 'olstoy'.
't'+'olstoy'='TOLSTOY'
'in' is the link.
(Other definitions for tolstoy that I've seen before include "Lost toy belonging to Count Leo, writer" , "He wrote Anna Karenina" , "Great Russian author of 'War and Peace'" , "Count Leo . . . . . . ., author of 'War and Peace'" , "Count Leo . . . . . . . wrote 'War and Peace'" .)