A demanding or stimulating situation;
From day one we human beings are challenged by life until our death. The word "challenge" is not a simple word but it is ambiguous in a certain sense.
This Impatient plant has found itself a challenge growing from a crevice where the seed has lodged itself. It battles other challenges like being eaten by voracious grasshopper who likes its tender green leaves
Word History:
Middle English borrowed chalenge from Old French. French chalenge came from Latin calumnia "trickery, false accusation", a noun based on the verb calvi "to deceive". So a challenge was originally a false accusation.
The sense of confrontation carried on but the general meaning of this word moved from a negative to a positive sense somewhere along the way between Latin and English. http://www.alphadictionary.com/goodword/
The goldfish in the pond face every day the challenge to escape being a meal to a silver gray heron. I have made them hide away places to give the challenged fish a chance to escape.
Are you facing any challenges at the moment?