Child keeps writing in only binder (10)
I believe the answer is:
tourniquet
'binder' is the definition.
(thesaurus)
'child keeps writing in only' is the wordplay.
I cannot really see how this works, but
'writing' could be 'r' (one of the traditional three R's of education) and 'r' is present in the answer.
'only' could be 'unique' (synonyms) and 'unique' is found within the leftover letters.
'child' could be 'tot' (term for a young child) and 'tot' is present in the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tourniquet that I've seen before include "it'll stop bleeding" , "Device for stopping blood flow" , "bleeding controller!" , "Blood-staunching compressor" , "Compression bandage" .)