space walk

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An excursion by an astronaut outside a spacecraft in space; extravehicular activity.

from the GNU version of the Collaborative International Dictionary of English.

• noun any activity by a human outside of the protective environment of a spacecraft while it is in outer space, requiring a space suit to protect the person from the vacuum and other hazards of space.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any activity performed by an astronaut outside of a space vehicle in space.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any kind of physical activity outside a spacecraft by one of the crew