Prison initially caused everyone to cry (8)
I believe the answer is:
birdcall
'cry' is the definition.
(thesaurus)
'prison initially caused everyone' is the wordplay.
'prison' becomes 'bird'.
'initially' suggests taking the first letters.
'everyone' becomes 'all' (all people).
The initial letter of 'caused' is 'c'.
'bird'+'c'+'all'='BIRDCALL'
'to' acts as a link.
(Other definitions for birdcall that I've seen before include "Sound of tweeters" , "(Instrument copying) songster's song" , "(Device to imitate) song of songster" .)