Given signal, crooked dealer brings in tons (7)
I believe the answer is:
alerted
'given signal' is the definition.
(I've seen this before)
'crooked dealer brings in tons' is the wordplay.
'crooked' indicates anagramming the letters.
'brings in' indicates putting letters inside.
'tons' becomes 't'.
'dealer' anagrammed gives 'alered'.
'alered' placed around 't' is 'ALERTED'.
(Other definitions for alerted that I've seen before include "Given signal" , "Given warning" , "Altered, having been put on guard" , "Warned, made aware" , "Put on guard, raised the alarm" .)