One can't sleep through it (8)

I believe the answer is:

insomnia

'one can't sleep through it' is the definition.
(insomnia prevents people from sleeping)

This is the entire clue.

(Other definitions for insomnia that I've seen before include "Condition affecting sleep" , "State of chronic sleeplessness" , "problem at night" , "Inability to drop off" , "Wakefulness" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app