Definition of disbelieving in English:
 disbelieving
adjectiveˌdɪsbɪˈliːvɪŋˌdɪsbəˈlivɪŋ
- Feeling or expressing disbelief. -  the disbelieving look in her eyes 
-  Example sentencesExamples -  They wanted a holiday snap to show disbelieving folks back home what looked almost like the parting of the waters by Moses.
-  Jennifer offered a brief narrative but received a disbelieving glance.
-  Only on this occasion, the disbelieving doctor called the police.
-  The soldier is looking very disbelieving; he is barking again.
-  Bert was stunned as the surreal scene continued to unfold in front of his bleary, disbelieving eyes.
-  Mom and Dad gasped and stared at me with disbelieving eyes.
-  I played back the message for my disbelieving friends.
-  A late night call conveyed the good news to a disbelieving Carmel who proved a very popular winner.
-  All the same, it was good to see Kev finally faced with disbelieving opposition.
-  The next day, he shows the letter to his disbelieving doctor.
-  I have the manic, disbelieving smile of a winning game-show contestant.
-  Indeed, if he dismisses it with a disbelieving laugh, we expect to see the bad luck drop on him out of the blue.
-  Elizabeth interjected, giving her mother a disbelieving stare.
-  Somehow he must convince a disbelieving world that the nightmare has already begun.
-  Brice let out a high, disbelieving laugh.
-  An hour later a delirious and disbelieving Beryl rang again.
-  Janet's expression softened as she regarded her disbelieving companion.
-  The handful of coaches, scouts and parents were stunned into disbelieving silence before breaking into thunderous applause.
-  She stiffened slightly when she heard her father's disbelieving snort.
-  I could tell from their disbelieving faces that they couldn't believe how generous I was.
 
Derivatives
  
adverb
-  ‘Twenty years in local government,’ he whispers disbelievingly. 
-  Example sentencesExamples -  Another asked, disbelievingly: ‘Surely he doesn't think he can get away with that kind of thing?’
-  He shakes his head disbelievingly - then he hands our passports back.
-  My new boss laughs, disbelievingly, but I patiently explain I'd been invited to a singles night comprising of rising marketing professionals such as myself.
-  Sara stared at me incredulously for a second before shaking her head disbelievingly.
 
Definition of disbelieving in US English:
 disbelieving
adjectiveˌdisbəˈlēviNGˌdɪsbəˈlivɪŋ
- Feeling or expressing disbelief. -  the disbelieving look in her eyes 
-  Example sentencesExamples -  Mom and Dad gasped and stared at me with disbelieving eyes.
-  The soldier is looking very disbelieving; he is barking again.
-  She stiffened slightly when she heard her father's disbelieving snort.
-  Indeed, if he dismisses it with a disbelieving laugh, we expect to see the bad luck drop on him out of the blue.
-  Elizabeth interjected, giving her mother a disbelieving stare.
-  They wanted a holiday snap to show disbelieving folks back home what looked almost like the parting of the waters by Moses.
-  An hour later a delirious and disbelieving Beryl rang again.
-  All the same, it was good to see Kev finally faced with disbelieving opposition.
-  Somehow he must convince a disbelieving world that the nightmare has already begun.
-  I could tell from their disbelieving faces that they couldn't believe how generous I was.
-  I have the manic, disbelieving smile of a winning game-show contestant.
-  I played back the message for my disbelieving friends.
-  Only on this occasion, the disbelieving doctor called the police.
-  A late night call conveyed the good news to a disbelieving Carmel who proved a very popular winner.
-  Jennifer offered a brief narrative but received a disbelieving glance.
-  Brice let out a high, disbelieving laugh.
-  The handful of coaches, scouts and parents were stunned into disbelieving silence before breaking into thunderous applause.
-  The next day, he shows the letter to his disbelieving doctor.
-  Janet's expression softened as she regarded her disbelieving companion.
-  Bert was stunned as the surreal scene continued to unfold in front of his bleary, disbelieving eyes.