on one's guard

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Related to on one's guard: warship
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.On one's guard - vigilanton one's guard - vigilant; "on guard against con artists"; "must remain on your guard in such a situation"
wary - marked by keen caution and watchful prudence; "they were wary in their movements"; "a wary glance at the black clouds"; "taught to be wary of strangers"