3
observant(adjective, keen, alert, careful, restless)
3
slumberless(adjective, awareness)
3
tossing and turning(expression, adjective, idiom, unsettled, restless)
3
unquiet(adjective, anxious, unsettled, restless, uneasy)
2
alive
2
anxious(adjective, keen, alert, careful, unsettled)
2
bustling(adjective, anxious, unsettled, restless, uneasy)
2
cautious(adjective, keen, alert, careful, attentive)
2
guarded(keen, anxious, alert, careful, cautious)
2
insomnia
2
keen(anxious, alert, careful, cautious, attentive)
2
on guard(expression, keen, anxious, alert, careful)
2
on the alert(expression, idiom, alert, careful, restless)
2
on the ball(expression, idiom, keen, alert, careful)
2
on the job(expression, idiom, keen, alert, careful)
2
on the lookout(expression, idiom, keen, alert, careful)
2
open-eyed(keen, anxious, alert, careful, cautious)
2
sharp(keen, anxious, alert, careful, attentive)
2
waking
1
acute(keen, anxious, alert, careful, cautious)
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APASmart Define. (2015). sleepless thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/sleepless/thesaurus/synonyms
ChicagoSmart Define. 2015. "sleepless thesaurus" https://smartdefine.org/sleepless/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, sleepless thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/sleepless/thesaurus/synonyms>.
MLASmart Define. "sleepless thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/sleepless/thesaurus/synonyms>