challenge

challenge

1. US an assertion that a person is not entitled to vote or that a vote is invalid

2. Law a formal objection to a person selected to serve on a jury (challenge to the polls) or to the whole body of jurors (challenge to the array)

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

challenge

[′chal·ənj]

(communications)

To cause an interrogator to transmit a signal which puts a transponder into operation.

(immunology)

Administration of an antigen to ascertain state of immunity.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.