conservative  
adjective uk/kənˈsɜː.və.tɪv/ us/kənˈsɝː.və.t̬ɪv/
  (AGAINST CHANGE)         
 C1 保守的;守旧的
not usually liking or trusting change, especially sudden change
  a conservative society/outlook 保守的社会/观念 
 Older people tend to be more conservative and a bit suspicious of anything new. 上年纪的人往往很保守,对任何新的东西都有些怀疑。 
 Compare: liberal adjective (SOCIETY)
  (外表上)保守的,传统的,不赶潮流的
If you are conservative in your appearance, you usually do not like fashionable or modern clothes or hairstyles.
  He's a very conservative dresser - he always looks like he's wearing his father's clothes! 他穿着十分保守——看上去总像是穿着他父亲的衣服! 
 - More examples
 - He has a very conservative approach to management.
 - She's very conservative in her eating habits.
 - When it comes to music, my tastes are quite conservative.
 
  (LOW)      
 (猜测、计算)保守的,低估的
A conservative guess or calculation is likely to be less than the real amount.
  If I said there were three million unemployed, that would be a conservative estimate. 我要是说失业人数有300万的话,那是保守估计。