summate summate /ˈsʌmˌmeɪt/

verb

1. () Determine the sum of  ( add together , sum , sum up , add , summate , tally , tot , tot up , tote up , add up , total )
   determine the sum of
    Add all the people in this town to those of the neighboring town
   Add all the people in this town to those of the neighboring town
   
2. Form or constitute a cumulative effect  ( summate )
   form or constitute a cumulative effect