boyau /bwoˈyō, bwäˈyō or boiˈō/ (fortification)

A communication trench

• heliospheres
• heliospheric
• heliostat
• heliostats
• heliotaxes
• heliotaxis
• heliotherapies
• heliotherapy
• heliotrope
• heliotropes
• heliotropic
• heliotropical
• heliotropically
• heliotropies
• heliotropin
• heliotropins
• heliotropism
• heliotropisms
• heliotropy
• heliotype
• heliotypes
• heliotypic
• heliotypies
• heliotypy
• Heliozoa