As verbs the difference between add and adde
is that
add is to join or unite, as one thing to another, or as several particulars, so as to increase the number, augment the quantity, or enlarge the magnitude, or so as to form into one aggregate. Hence: To sum up; to put together mentally while
adde is obsolete spelling of lang=en.
As a noun add
is an additional enemy that joined the fight after the primary target.