"Dim and wonderful is the vision I have conjured up in my mind of life spreading slowly from this little seed-bed of the solar system throughout the inanimate vastness of sidereal space. But that is a remote dream."
— H. G. Wells, War of the Worlds
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sider(o)- combining form (from Gk sideros) iron (cf. siderism, siderite)
sidero- combining form (from L. sidus) star (cf. sidereal, sideromancy, siderostat)