An underground vertical shaft leading upward from a cave passage or cave chamber, which often connects with other passages or shafts above and may be the underground entry point for recharge waters from a sinkhole, streamsink or swallet.
Found on http://www.cancaver.ca/docs/glossary.htm


Aven (ā'ven) , in the Bible, abusive name applied to towns: to Bethel (see Beth-aven); to Heliopolis in Egypt in the Book of Ezekiel; and to some other place, traditionally Baalbek, in the Book of Amos.
Found on http://www.infoplease.com/ce6/society/A0805451.html


Axisymmetric Vectoring Exhaust Nozzle, a vectoring nozzle for the GE F-101 engine [US]
Found on http://www.jedsite.info/index.html
No exact match found