flehmen
Flaring of the lip in mammals, associated with intensive smelling; flehming.
countable, uncountable
During the preliminary phase of courtship between captive animals, Matthew Gaughwin observed flehmen on a number of occasions when the male sniffed intensely at areas of ground where the female had previously urinated and once when the male had sniffed the female's cloacal region.
Where it comes from
From German flehmen, from Upper Saxon German flemmen (“to look spiteful”).
Adapted from the Wiktionary entry flehmen (CC BY-SA 4.0).