1. 
[syn: adversity, hardship, hard knocks]
2.  a stroke of ill fortune;  a calamitous event; 
- Example: "a period marked by adversities"
The Collaborative International Dictionary of English v.0.48:
Adversity \Ad*ver"si*ty\, n.; pl. Adversities. [OE. adversite,
   F. adversit['e], fr. L. adversitas.]
   1. Opposition; contrariety. [Obs.] --Wyclif.
      [1913 Webster]
            Adversity is not without comforts and hopes.
                                                  --Bacon.
      [1913 Webster]
   Syn: Affliction; distress; misery; disaster; trouble;
        suffering; trial.
        [1913 Webster]
WordNet (r) 3.0 (2006):
adversity
    n 1: a state of misfortune or affliction; "debt-ridden farmers
         struggling with adversity"; "a life of hardship" [syn:
         adversity, hardship, hard knocks]
    2: a stroke of ill fortune; a calamitous event; "a period marked
       by adversities"