in ‧ cred ‧ u ‧ lous /ɪnˈkredjələs, ɪnˈkredjʊləs $ -dʒə-/ BrE AmE adjective
[ Word Family: adverb : ↑ incredibly , ↑ credibly , ↑ incredulously ; adjective : ↑ incredible , ↑ credible , ↑ incredulous ; noun : ↑ credibility , ↑ incredulity ]
unable or unwilling to believe something:
‘You sold the car?’ she asked, incredulous.
incredulous look/expression/voice etc
She shot him an incredulous look.
—incredulously adverb