This example returns a list of antonyms for the word "big" in U.S. English.
Alist = SynonymInfo(Word:="big", _
LanguageID:=wdEnglishUS).AntonymList
For i = 1 To UBound(Alist)
Msgbox Alist(i)
Next i
This example returns a list of synonyms for the selection's first meaning.
Slist = Selection.Range.SynonymInfo.SynonymList(Meaning:=1)
For i = 1 To UBound(Slist)
Msgbox Slist(i)
Next i