Merriam-Webster's Collegiate Dictionary
su·per·add
\\ˌsü-pər-ˈad\\ transitive verb ETYMOLOGY Middle English, from Latin superaddere, from super- + addere to add
DATE 15th century
: to add especially in a way that compounds an effect
the loss of his job was superadded to the loss of his house Webster's Third New International Dictionary, Unabridged
su·per·add
\“+\ transitive verb
Etymology: Middle English superadden, from Latin superaddere, from super- + addere to add
1. : to add over and above : add in extra or superfluous amount
< the loss of his position was superadded to the loss of his home >
< a superadded ornamentation >
2. : to make an addition; specifically : to say in addition : add to what has been mentioned