genus /jēˈnəs or jenˈəs/

1. A taxonomic group of lower rank than a family, consisting of closely related species, in extreme cases of one species only (biology)
2. A class of objects comprehending several subordinate species (logic)

• head boy
• head boys
• head-bummer
• head-butt
• head-butted
• head-butting
• head-butts
• headcase
• headcases
• head-centre
• headchair
• headchairs
• headcheese
• headcheeses
• headcloth
• headcloths
• head cold
• head colds
• head count
• head counts
• head-crash
• head-crashes
• head-down display
• headdress
• headdresses