Guard = to keep safe from harm or danger; protect; watch over; to keep under close watch in order to prevent escape, misconduct, etc; to keep under control or restraint as a matter of caution or prudence; to provide or equip with some safeguard or protective appliance, as to prevent loss, injury, etc.
Synonyms: Protect, safeguard, security, watch, lookout, alert, sentry,
Example: Online shoppers fail to guard against fraud.
Usage in Sentence: Guard against, not from.
Don’t say: You must guard from bad habits.
ü Say: You must guard against bad habits.