Dissemble
Etymology
An alteration of earlier "dissimule," from Latin dissimulare, "to disguise, conceal," from dis- plus simulare, "to feign, make like," from similis, "like." Its spelling was pulled toward "resemble." Where to simulate is to feign what is not there, to dissemble is to hide what is — putting on a mask over the real feeling.
verb · /dih-SEM-bul/
To hide one’s true feelings, thoughts, or intentions behind a false show.
What it names
The word for concealment by pretense — masking what you actually think or feel rather than telling an outright lie.
Example
He dissembled his disappointment, congratulating the winner with a smile that cost him something.
Related idea
Dissemble hides what you feel; to simulate is to fake a feeling you don’t have — concealment versus counterfeit.