alert
awake
shallow
watchful
agile
alive
attentive
bright
insomniac
insomnious
keen
nimble
on the
on the alert
on the ball
on the job
prompt
qui vive
quick
ready
restless
roused
sharp
sleepless
slumberless
smart
unblinking
unnodding
unsleeping
unwinking
vigilant
waking
wide-awake
apprehensive
despondent
dissatisfied
distraught
distrustful
downcast
dreamless
edgy
excitable
fevered
fitful
fretful
haggard
homesick
jumpy
sleepy
uneasy
unquiet
unsure
wary