testing

adj

1. Difficult; tough.

   “England have now gone four games without a win at Wembley, their longest sequence without a victory in 30 years, and still have much work to do to reach Euro 2012 as they prepare for a testing trip to face Bulgaria in Sofia in September.”

noun

1. (countable, uncountable)The act of conducting a test; trialing, proving.

   “The wilderness testings of Jesus prepare him for ministry in which such temptations and shortcuts will recur.”

verb

1. (form-of, gerund, participle, present)present participle and gerund of test