
1) Modifying agent
Found on
https://www.crosswordclues.com/clue/temperer

• (n.) One who, or that which, tempers; specifically, a machine in which lime, cement, stone, etc., are mixed with water.
Found on
http://thinkexist.com/dictionary/meaning/temperer/
Tem'per·er noun One who, or that which, tempers; specifically, a machine in which lime, cement, stone, etc., are mixed with water.
Found on
http://www.encyclo.co.uk/webster/T/23
No exact match found.