Advertisement Upgrade to remove ads


a plane with one set of wings


having one sound or tone


a vehicle with a single wheel that is driven by pedals


(economics) a market in which there are many buyers but only one seller


of one color


using or knowing only one language


the quality of being united into one


(adj.) one of a kind; unequaled; unusual; found only in a given class, place, or situation


all of space and everything in it


the same throughout in structure or composition

Flickr Creative Commons Images

Some images used in this set are licensed under the Creative Commons through Click to see the original works with their full license.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording