Dissimulate
/dɪˈsɪmjuleɪt/
Definition 1 of 1
Pro Tip 1/3Emotional camouflage
Dissimulate is used when someone hides their emotions to deceive or to maintain harmony. 
Despite feeling upset, he dissimulated happiness at his friend's success.
Pro Tip 2/3Strategic responses
Sometimes dissimulate is used strategically, such as in politics or negotiations, to hide true plans. 
The diplomat had to dissimulate his intentions during the talks.
Pro Tip 3/3Negative connotation
To dissimulate often has a negative connotation, suggesting dishonesty or a lack of authenticity. 
He was disliked because he often dissimulated his discontent.