Single, appearing for the first time, extremely arty, after love … (3-3)
I believe the answer is:
one-way
'single' is the definition.
(as in a single train ticket)
'appearing for the first time extremely arty after love' is the wordplay.
'appearing for the first time' becomes 'new' (something brand new making a debut appearance).
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'after' means one lot of letters go next to another.
'love' becomes 'o' (love means zero in tennis).
'arty' with its middle taken out is 'ay'.
'new'+'ay'='neway'
'neway' put after 'o' is 'ONE-WAY'.
(Other definitions for one-way that I've seen before include "Unidirectional" , "Allowing travel in one direction only" , "Moving in a single direction only" , "Street allowing traffic in single direction only" , "Only travelling in the same direction" .)