To sovle this question, we need to know what it is asking us. Since the quesiton is asking us what something is, we know that it is asking for the definition of the word. We can figure out the meaning using roots and common words.
De is the latin root for down, and off.
Toxic is a word describing something hazardous in nature.
ification means the proccess of.
Using this, we can conclude the detoxification is the process of taking off (removing) something hazardous.