Poet’s line recalled in good French (5)
I believe the answer is:
byron
'poet's' is the definition.
(Lord Byron)
'line recalled in good french' is the wordplay.
'line' becomes 'ry' (abbreviation for railway).
'recalled' says the letters should be written backwards.
'in' means one lot of letters goes inside another.
'good french' becomes 'bon' ('good' in French).
'ry' back-to-front is 'yr'.
'yr' placed into 'bon' is 'BYRON'.
(Other definitions for byron that I've seen before include "Lord George, poet" , "English poet, said to be 'mad, bad, and dangerous to know', d. 1824" , "Romantic poet, helped Greeks" , "English romantic poet, d. 1824" , "Author of 'Don Juan'" .)