There's no turning back! (3-3)
I believe the answer is:
one-way
'there's no turning back' is the definition.
I can't judge whether this definition defines the answer.
'no turning back' is the wordplay.
'no' becomes 'one' (I am not sure about this - if you are sure you should believe this answer much more).
'turning' becomes 'yaw' (yaw is a kind of turning).
'back' shows that the letters should be reversed in order.
'yaw' back-to-front is 'way'.
'one'+'way'='ONE-WAY'
Can you help me to learn more?
(Other definitions for one-way that I've seen before include "Like non-return valve" , "Moving in a sole direction" , "Only travelling in the same direction" , "Single-directional like some streets" , "Describing a street where vehicles shouldn't meet head-on" .)