1. (followed by “over”) . to make a close intent examination or study (of a book, map, etc.)
2. (followed by “over” or “upon”) . to think deeply (about)
3. (followed by “over”, “on”, or “upon”) (rare) . to look earnestly or intently (at); gaze fixedly (upon)
1. (anatomy, zoology) any small opening in the skin or outer surface of an animal
2. (botany) any small aperture, especially that of a stoma through which water vapour and gases pass
3. any other small hole, such as a space in a rock, soil, etc.