Means "many loves." Briefly, a polyamorous person is one who feels it is natural to romantically love more than just one person at a time. A polyamorous person may have more than one person that s/he considers to be a "spouse," for example. Polyamory is about love, without constraint by the dictates of society, defined only by the parameters that we, as individuals, impose upon it.
In other words, anything goes!