killas /kilˈəs/ (geology)

Clay-slate

• furtively
• furtiveness
• furtivenesses
• furuncle
• furuncles
• furuncular
• furunculoses
• furunculosis
• furunculous
• fury
• furze
• furzes
• furzier
• furziest
• furzy
• fusain
• horsts
• horsy
• hortation
• hortations
• hortative
• hortatively
• hortatorily
• hortatory
• horticultural