[{"Bold_text": "preposition", "List Items": ["to place or position on ;upon; on:to get onto a horse.", "Informal.in or into a state of awareness about:I'm onto your scheme."]}, {"Bold_text": "adjective", "List Items": ["Also .Mathematics.pertaining to a function or map from one set to another set, the range of which is the entire second set."]}, {"Bold_text": null, "List Items": ["a combining form meaning “being,” used in the formation of compound words:ontogeny."]}]