monocotyledon, monocots A plant with one cotyledon or seed leaf. A very important group of flowering plants, dominating great parts of the earth and with many economically important plants. The largest monocot family is the Orchidaceae (orchids), with very complex (and striking) flowers, for highly specific insect pollination. The second largest a... Found on http://www.wordinfo.info/words/index/info/view_unit/552/