What does candid mean?

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From our dictionary:

can•did

Pronunciation: (kan'did), [key]
adj.
1. frank; outspoken; open and sincere: a candid critic.
2. free from reservation, disguise, or subterfuge; straightforward: a candid opinion.
3. informal; unposed: a candid photo.
4. honest; impartial: a candid mind.
5. Archaic.white.
6. Archaic.clear; pure.

n.
an unposed photograph.