second hand

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

• noun The hand on a clock or watch that marks the seconds.
• noun An intermediary person or source.

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

• adjective Alternative form of secondhand.
• noun On a clock or watch, the hand or pointer that shows the number of seconds that have passed.

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

• noun hand marking seconds on a timepiece
• adverb from a source of previously owned goods
• noun an intermediate person; used in the phrase `at second hand'