in·sin·cere
adjective/ˌɪnsɪnˈsɪə(r)/
/ˌɪnsɪnˈsɪr/
(disapproving)- saying or doing something that you do not really mean or believe
不诚恳的；不真心的 - an insincere smile
虚情假意的微笑
Word Originmid 17th cent.: from Latin insincerus, from in- ‘not’ + sincerus ‘sincere’. - an insincere smile