Sublist 1 of the Academic Word List Part 2

involve involved                 occur occurred             reoccurred               role roles
          involvement                     occurrence         reoccurring
          involves                          occurrences        reoccurs
          involving                         occurring
          uninvolved                       occurs

research researched           significant insignificant                         specific specifically
             researcher                          insignificantly                                   specification
             researchers                        significance                                      specifications
             researches                         significantly                                      specificity
             researching                        signified                                           specifics
                                                     signifies
 vary  invariable                               signify
         invariably                                signifying
         variability
         variable
         variables
         variably
         variance
         variant
         variants
         variation
         variations
         varied
         varies
         varying