pretendShe pretended not to know about the surprise.
make believeHe's just going to make believe that things are fine in spite of the divorce.
play at somethingUKThe children are playing at cops and robbers.
role-playDuring class, we role-played being a customer and a salesperson to learn words related to shopping.
fakeShe's only faking being ill.
feignThe police questioned him about the break-in, but he feigned ignorance.
affectformalHis friends only affected interest in his problems.
dissimulateformalThe government appears to be dissimulating regarding their intentions behind drone strikes.
dissembleformalThe prince demanded to know if she loved him, but she shyly dissembled.
keep up appearancesThey've just lost their house, but they're still keeping up apperances for their relatives.
pose as someoneShe was posing as a member of the aristrocracy in order to steal money from the rich.
impersonateThe suspect was charged with impersonating a police officer.