Reddendum

• (n.) A clause in a deed by which some new thing is reserved out of what had been granted before; the clause by which rent is reserved in a lease.
Found on http://thinkexist.com/dictionary/meaning/reddendum/

Reddendum

Red·den'dum noun [ Neut. of Latin reddendus that must be given back or yielded, gerundive of reddere . See Reddition .] (Law) A clause in a deed by which some new thing is reserved out of what had been granted before; the clause by which rent is reserved in a lease.
Found on http://www.encyclo.co.uk/webster/R/30

reddendum

reserving clause in a lease
Found on http://phrontistery.info/r.html
No exact match found