Hollowly
/ˈhɑːləʊli/
Definition 1 of 1
Pro Tip 1/3Emotional Disconnection
Used when someone is emotionally detached or doesn't genuinely feel the emotions they are displaying. 
He congratulated me hollowly on my promotion, his envy barely hidden.
Pro Tip 2/3Disguising Truth
Often implies the speaker is hiding their true feelings or lying through a forced show of emotion. 
Her apology was hollowly spoken, leaving me doubting its sincerity.
Pro Tip 3/3Contrasting Actions
Can be used to highlight a discrepancy between someone's words and their actions. 
She spoke of kindness hollowly, while her actions were cruel.