sniff out something
— phrasal verb with sniff us/snɪf/verb [ I/T ]
to discover something, usually only after a special effort:
Professors are always trying to sniff out plagiarized term papers.
英语词典包含110679条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。