The following:

\starttext
Fate\index{Fate} 
and 
Destiny\seeindex{Destiny}{Fate}
\blank[3*big]
\placeindex
\stoptext

produces an entry for “Destiny” that reads:

d
Destiny
     Fate    see Fate

If one comments out “Fate\index{Fate}”, the entry reads as it should:

d
Destiny
      see Fate

Is there a way to cross-reference an indexed term X that has only 
            see X
and not 
            X see X?

Alan