I’m chum you are texting inside, awaiting development (8)
I believe the answer is:
immature
'awaiting development' is the definition.
I can't tell whether this defines the answer.
'i'm chum you are texting inside' is the wordplay.
'chum' becomes 'mate' (I've seen this in another clue).
'you are texting' becomes 'ur' (abbreviation for 'you are' when texting).
'inside' indicates putting letters inside.
'mate' placed around 'ur' is 'mature'.
'im'+'mature'='IMMATURE'
Can you help me to learn more?
(Other definitions for immature that I've seen before include "Not yet adult or fully developed" , "Not yet adult or fully grown" , "Undeveloped - unripe" , "Like childish behaviour" , "Not yet fully-developed" .)