Quoting from Wikipedia, the definition for this two word term from aeronautics is:
an aerial maneuver in which an airplane makes a complete rotation on its longitudinal axis while following a helical path, approximately maintaining its original direction. It is sometimes described as "a combination of a loop and a roll".
This term became part of an internet sensation in November 2011. What term and why the hooplah?
[+ Show Answer]
The term is "barrel roll". Google revealed a new "easter egg" in which one could type "do a barrel roll" on the Google search engine (on reasonably modern browsers such as Chrome or new Firefox versions) to cause the page to imitate a "barrel roll". Apparently,
this was also a tribute to the video game StarFox.