word-forming element typically representing cross as a noun, adverb (cross-examine), adjective (crossbar), and in many words a confluence of them. "There is no distinct line of division between cross as an adjective and cross as a prefix. As a prefix, it often represents the adv. cross, or the prep. cross, across." [Century Dictionary]
in botany, "the supplying of pollen to a female organ; act of pollinating," especially "fertilization of plants by the agency of insects," 1872, from older French pollination, noun of action formed 1812 from pollin-, stem of Latin pollen (see pollen). Also pollenation. Replaced in Modern French by pollinisation.
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Definitions of cross-pollination from WordNet
fertilization by transfer of pollen from the anthers of one flower to the stigma of another;