Yet to follow a French irregular (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
uneven
'irregular' is the definition.
('uneven' can be similar in meaning to 'irregular')
'yet to follow a french' is the wordplay.
'yet' becomes 'even' ('even' can be a synonym of 'yet').
'to follow' means one lot of letters go next to another.
'a french' becomes 'un' ('a' in French).
'even' put after 'un' is 'UNEVEN'.
(Other definitions for uneven that I've seen before include "Asymmetrical, not uniform" , "Rough, jagged" , "Inconsistant in quality" , "Patchy" , "Irregular or not smooth" .)