Definition of "spoor"

We all stopped to examine that monstrous spoor. If it were indeed a bird - and what animal could leave such a mark? - its foot was so much larger than an ostrich's that its height upon the same scale must be enormous.

1912, Arthur Conan Doyle, The Lost World […], London, New York, N.Y.: Hodder and Stoughton

Even poor Nobs appeared dejected as we quit the compound and set out upon the well-marked spoor of the abductor.

1918 September–November, Edgar Rice Burroughs, “The Land That Time Forgot”, in The Blue Book Magazine, Chicago, Ill.: Story-press Corp.; republished as chapter VIII, in Hugo Gernsback, editor, Amazing Stories, (please specify |part=I, II, or III), New York, N.Y.: Experimenter Publishing, 1927,

Now he has picked up the spoor of drunken vomit and there is the doll sprawled against a wall, his pants streaked with urine.

1971, William S. Burroughs, The Wild Boys: A Book of the Dead, page 10

From the spoor, skilled trackers can deduce an individual's age, sex, physical condition, speed, and fatigue level, as well as the time of day it passed by.

2016, Joseph Henrich, chapter 5, in The Secret of Our Success […] , Princeton: Princeton University Press