sleuth

Short definition from Wiktionary

Noun

1. 1
   A detective.
2. 2
   A sleuthhound; a bloodhound.
3. 3
   An animal’s trail or track.
4. 4
   Slowness; laziness, sloth.
5. 5
   A group of bears.

Verb

1. 1
   To act as a detective; to try to discover who committed a crime, or, more generally, to solve a mystery.