The semantic neighborhood of w, denoted by N(w), is defined as the set of all words v which are considered sufficiently similar to w, satisfying sim(w,v)>s where s is a threshold (0.04 in our experiments).
rFF is then defined by: we identify all words v that are in the semantic neighborhood of w and are also characterized by f and sum their similarities to w. Notice that rFF is a sum of word similarity values rather than being a direct function of wordfeature association values (which is the more common approach).