Noun

1. Any plant which habitually breaks away from its roots in the autumn, and is driven by the wind, as a light, rolling mass, over the fields and prairies; as witch grass, wild indigo, Amaranthus albus, etc.

Adjective

1. Describing unwonted silence and inactivity. Often used of a situation when one makes a statement that is ignored or ill-received from one’s audience. Gives the impression that a tumbleweed has passed through the room, as the resultant silence is likened to that of a desolate desert.
   • 2000 January 21, "Plsntgrn" in alt.music.progressive, "Re: SOAR Budget (A Long Guestimate)" http://groups.google.com/group/rec.music.progressive/msg/c5bc2926d0712699:

     Putting an ad in the local paper that Spock's Beard and Arena are in town will get you a tumbleweed response and some wasted revenue.

   • 2005, Trevor Wright, How to Be a Brilliant English Teacher http://books.google.com/books?id=5V64WA533MoC, ISBN 041533246X, page 68:

     "Why do families argue?" may only induce the tumbleweed response. (Could you answer that question out of the blue?)