challenge

Definitions of challenge in various dictionaries:

noun - a demanding or stimulating situation

noun - a call to engage in a contest or fight

noun - questioning a statement and demanding an explanation

noun - a formal objection to the selection of a particular person as a juror

noun - a demand by a sentry for a password or identification

verb - take exception to

verb - issue a challenge to

verb - ask for identification

verb - raise a formal objection in a court of law

A call to engage in a contest, fight, or competition: a challenge to a duel.

An act or statement of defiance; a call to confrontation: a challenge to the government’s authority.

A demand for explanation or justification; a calling into question: a challenge to a theory.

A sentry’s call to an unknown party for proper identification.

A test of one’s abilities or resources in a demanding but stimulating undertaking: a career that offers a challenge.

A claim that a vote is invalid or that a voter is unqualified.

A formal objection to the inclusion of a prospective juror in a jury.

Immunology.

To call to engage in a contest, fight, or competition: challenged me to a game of chess.

To take exception to; call into question; dispute: a book that challenges established beliefs.

To order to halt and be identified, as by a sentry.

To take formal objection to (a prospective juror).

To question the qualifications of (a voter) or validity of (a vote).

To have due claim to; call for: events that challenge our attention.

To summon to action, effort, or use; stimulate: a problem that challenges the imagination.

To induce or evaluate an immune response in (an organism) by administering a specific antigen to which it has been sensitized.

To make or give voice to a challenge.

To begin barking upon picking up the scent.