Fanatical, or obsessed with one cause or idea to the exclusion of other concerns.
Of or relating to a monomaniac.
Refusing to move or to change one's opinion; obstinate; firmly resisting; persistent in doing something.
Of materials: physically stiff and inflexible; not easily melted or worked.
Stubbornness.
A disease of citrus trees characterized by stunted growth and misshapen fruit, caused by Spiroplasma citri.