嗅探犬

嗅探犬	xiù tàn quǎn	sniffer dog
嗅	xiù	to smell / to sniff / to nose
嗅探	xiù tàn	to sniff (in order to find sth)
探	tàn	to explore / to search out / to scout / to visit / to stretch forward
犬	quǎn	(literary) dog / Kangxi radical 94