You are more likely to get ill when your defences are low.
the body's defences against disease
2.
military fortifications
the city's defences
Examples of 'defences' in a sentence
defences
And this excludes the possibility of chemical weapons being used to further degrade defences.
McInnes, Colin NATO's Changing Strategic Agenda (1990)
Activists clad in blue boiler suits spent the morning taking down the defences to the site.
The Sun (2011)
All related terms of 'defences'
defence
Defence is action that is taken to protect someone or something against attack.
propugnation
defence
sea defences
walls , breakwaters and other measures designed to prevent coastal erosion
flood defences
structures such as dams , artificial channels , etc, built to protect an area from flooding
zone defence
a tactic whereby each player in a team defends a particular area of the pitch or field
civil defence
Civil defence is the organization and training of the ordinary people in a country so that they can help the armed forces, medical services, or police force, for example if the country is attacked by an enemy.
perceptual defence
the process by which it is thought that certain stimuli are either not perceived or are distorted due to their offensive , unpleasant , or threatening nature
anti-aircraft defence
military measures or resources aimed at destroying enemy aircraft
antiaircraft defense
military measures or resources aimed at destroying enemy aircraft