As a verb summate
is to sum, add up; perform a summation.
As a noun summae is
irregular plural of summa.
summate
English
Verb
(summat)
To sum, add up; perform a summation
To sum up, summarise
summae
English
Noun
(head)
(summa)
----
summa
English
Noun
(en-noun)
A comprehensive summary of, or treatise on a subject, especially theology or philosophy.
----