Webster's Revised Unabridged Dictionary · 1913

Roseola

Roseola , noun

[New Latin, dim. of Latin rosa a rose.]

(med.) A rose-colored efflorescence upon the skin, occurring in circumscribed patches of little or no elevation and often alternately fading and reviving; also, an acute specific disease which is characterized by an eruption of this character; -- called also rose rash.