14
watchful(adjective, adverb, keen, sharp, lively)
12
vigilant(adjective, adverb, sharp, bright, lively)
11
alert(adjective, adverb, keen, sharp, bright)
11
wary(adjective, adverb, keen, sharp, bright)
10
cautious(adjective, adverb, keen, alert, careful)
10
observant(adjective, adverb, keen, sharp, bright)
8
careful(adjective, adverb, keen, sharp, bright)
8
heedful(adjective, adverb, sharp, bright, lively)
7
circumspect(adjective, keen, sharp, bright, lively)
7
on the lookout(expression, adjective, idiom, adverb, sharp)
6
awake(adjective, alert, careful, restless, disturbed)
6
guarded(adjective, adverb, keen, anxious, alert)
5
attentive(adjective, keen, sharp, bright, lively)
5
on one's guard(adjective, adverb, wary)
4
gingerly(adjective, cautious, suspicious, watchful)
4
mindful(adjective, adverb, wary)
4
on the watch(expression, adjective, idiom, adverb, alert)
4
prudent(adjective, cautious, suspicious, watchful)
4
safe(adjective, cautious, suspicious, watchful)
3
all ears(expression, adjective, sharp, bright, lively)
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APASmart Define. (2015). on guard thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/on_guard/thesaurus/synonyms
ChicagoSmart Define. 2015. "on guard thesaurus" https://smartdefine.org/on_guard/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, on guard thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/on_guard/thesaurus/synonyms>.
MLASmart Define. "on guard thesaurus" 14 April 2015. Web. 20 September 2026. <https://smartdefine.org/on_guard/thesaurus/synonyms>