discreet, prudent

える(わきまえる) To know right from wrong. To know one’s place. To know one’s limitations. More like to be polite or respectful than to be
(しんちょう) Used with plans or projects. To proceed slowly and carefully, avoiding risk.
(しりょぶかい) Someone who is sensible, prudent, level-headed. Not used about affairs and discreet bribes and etc.
(ようじん) Although the dictionary says “discreet, careful, prudent、” 用心 is more like “Look out!” – like if your friend is all ninja-ing her way into the enemy territory, or traipsing through the minefield, you’d use this one.
IMPORTANT: None of these words has the bad connotation of the English ‘discreet’, which conjures up images of people having affairs or taking bribes discreetly. The Japanese words are only good. If you want to use the bad meaning of the English ‘discreet’, then you should go with こっそり (secretly). Or, if you’re about to meet your wife’s stuck-up boss for a dinner party, you wouldn’t use 慎重 or 弁える (unless you were being really rude!). You’d just say 気をつけないといけない。