Information in emergency (3)
I believe the answer is:
gen
'information' is the definition.
(gen can informally mean information)
'in emergency' is the wordplay.
'in' indicates the answer is hidden within the clue.
'GEN' is hidden within 'emergency'.
(Other definitions for gen that I've seen before include "Lowdown (sl.)" , "opening book, in short" , "Info" , "'Information, colloquially (3)'" , "Information (colloq.)" .)