1. on guard - Adjective
2. on guard - Adjective Satellite
vigilant
Source: WordNeton-guard
If a man has sinned and denies it, saying: 'I have not sinned,' do not reprimand him; for that will discourage him. But say to him, 'Do not lose heart, brother, but be on guard in future,' and you will stir his soul to repentance. Poemen
We must always be on guard lest, under the pretext of keeping one commandment, we be found breaking another. Basil of Caesarea
I can be on guard against my enemies, but God deliver me from my friends! Charlotte Brontë
As long as the mouse keeps still you can be sure that the cat stays on guard. Madagascan Proverb
You can't sleep and be on guard. Sicilian Proverb
He who possesses many things is constantly on guard. Sumerian Proverb