x1 is/are the thing(s) described/named with property x2 by the speaker, who thinks this is contextually enough information for the listener to understand what are x1's referent(s)
This predicate is intended to be the predicate equivalent of le (or at least to one of the interpretations thereof), so that «lo le'elkai be lo ka broda» is equivalent to «le broda». See also le, lemkai.