1) Of or pertaining to agrypnia 2) Vigil 3) Watch 
anything taken to aid wakefulness
• (n.) Anything which prevents sleep, or produces wakefulness, as strong tea or coffee.
Ag`ryp·not'ic noun [ Greek ... sleepless; ... to chase, search for + ... sleep: confer French agrypnotique .] Anything which prevents sleep, or produces wakefulness, as strong tea or coffee. 
[adj] - of or pertaining to agrypnia
agrypnotic 1. Anything administered to produce wakefulness; such as, strong tea or coffee. 2. Of or relating to wakefulness; sleepless.
adjective of or pertaining to agrypnia