dissemble

Verb

• behave unnaturally or affectedly
  • She's just acting
    

• hide under a false appearance
  • He masked his disappointment
    

• make believe with the intent to deceive
  • He feigned that he was ill
    
  • He shammed a headache
    

Related words

• Synonyms: 
  pretend , act , cloak , mask , feign , sham , affect