Elite, to me, means being able to pull from across the country in your admissions and being recognized for strong research or strong teaching ability.
Universities:
the Ivies, Stanford, MIT, Chicago, Duke, Vandy, Rice, Caltech, Northwestern, UCB, UMich, UCLA, and some that I’m sure I’m forgetting (but does that mean they’re still elite?).
LACs:
Williams, Amherst, Swarthmore, the Claremonts, Wellesley, Vassar, Wesleyan, Bowdoin, Middlebury, and maybe a couple more. LACs have a much harder time than major research universities at hitting the first criterium, and perhaps a marginally easier time with the second.