► 名詞禁物  [きんもつ]  [liter]    
meaning:  prohibit  rank: 3☆ 
慢心は禁物 ⇨ Complacency is prohibited. Never be complacent  
(☛ Usually used for life lessons)More examples:- 過信は禁物 ⇨ You should never be too sure of anything
 - 結婚に焦りは禁物 ⇨ You can’t hurry trying to get married
 - 油断は禁物だ ⇨ Never let your guard down