look up any word, like the eiffel tower:
a very old woman (like 60+) that still goes after young men. A siberian tiger is much older than a cougar, bobcat, or mrs. robinson, probably along the lines of a GILF.
I've been banging this cougar lately, shes like 68.

Bro thats too old for a cougar, shes is a siberian tiger.
by Neege June 23, 2007
The act of riding a bike up someones anus
I'm so sore after Dave siberian tiger'd me last night
by positive1 September 26, 2010