whiff         
noun [ C usually singular ] uk/wɪf/ us/wɪf/
 一阵气味,一股味道
a slight smell, carried on a current of air
  He leaned towards me and I caught/got a whiff of garlic. 他向我靠过来,我闻到一股大蒜的味道。 
 During the first few months of pregnancy the slightest whiff of food cooking made my stomach turn. 怀孕的最初几个月,闻到一点点做饭的味道就会让我反胃。 
 a whiff of something 一点点,些许
a slight sign of something
  They regularly hold elections without a whiff of corruption or violence. 他们定期举行选举,其中毫无腐败或暴力的成分。