atyp·i·cal
 /eıˈtıpıkəl/  adj  
  : not typical : not usual or normal
   an atypical case
   This book is atypical of her previous work. [=is not like her previous work]
  atyp·i·cal·ly /eıˈtıpıkli/  adv  
   We had an atypically [=unusually] leisurely lunch that afternoon.