1892, scientific Latin; "in a test tube, culture dish, etc.;" literally "in glass," from Latin vitrum "glass" (see vitreous).
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vitreous adj.
early 15c., "glasslike," from Latin vitreus "of glass, glassy," from vitrum "glass," which perhaps was so called for its color (compare vitrium "woad"). Vitreous humor attested from 1660s.