Some careless language? (5)
I believe the answer is:
slang
'some careless language?' is the definition.
'slang' can be an answer for 'language?' (slang is a kind of language). I am not certain of the 'some careless' bit.
'some careless language?' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'SLANG' is hidden within 'careless language'.
Can you help me to learn more?
(Other definitions for slang that I've seen before include "colloquialisms" , "type of language?" , "... to scold" , "Informal speech" , "Informal language used by a set of people" .)