Go to MSN Homeencarta®
Dictionary
Find
in
Dictionary
Thesaurus
Translations
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Click to move up the list of words
backcomb
backcountry snowboarding
backcourt
backcross
backdam
backdate
backdoor
backdoor listing
backdoor selling
backdown
backdrop
backed
backer
backfield
backfile
backfill
backfire
Click to move down the list of words
Also available:

World English Dictionary
Dictionnaire Français

background radiation
back·ground ra·di·a·tion


noun 
Definition:
 
weak radiation from environment: low-level radiation occurring naturally as a result of radioactivity present in the air, soil, and buildings and other structures
Encarta® World English Dictionary [North American Edition] © & (P)2009 Microsoft Corporation. All rights reserved. Developed for Microsoft by Bloomsbury Publishing Plc.
Advertisement
© 2009 Microsoft