Typical old European endlessly on line (6)
I believe the answer is:
normal
'typical' is the definition.
('normal' can be similar in meaning to 'typical')
'old european endlessly on line' is the wordplay.
'old european' becomes 'yugoslavian' (I've seen this before).
'endlessly' means to look at the middle letters (the ends of the words are removed).
'on' says to put letters next to each other.
'line' becomes 'norma' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The central letter of 'yugoslavian' is 'l'.
'l' put after 'norma' is 'NORMAL'.
Can you help me to learn more?
(Other definitions for normal that I've seen before include "Commonplace" , "'Usual, standard (6)'" , "Standard - well-adjusted" , "'Standard, conventional (6)'" , "Regular" .)