A widget consisting of a static image that animates during execution of a task.(noun)
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Use "throbber" in a sentence
"Just watch the little blue circle next to the menu you just selected from (it's called a "throbber" and indicates that your selection is being recorded in the background)."
"i did that with my soundwave xsplash. the background's just plain black, so why do i need all those images? and the throbber was the same size as well."
"The build will start, the webdev environment will start up, a new tab will open in ff, the 'throbber' will run, and I can see the message 'Waiting for www. localhost.com ...' appear."