1.
If an injury or illness is left ~, it is not given medical treatment.
If left ~ the condition may become chronic.
...the consequences of ~ tuberculosis.
ADJ: ADJ after v, ADJ n, v-link ADJ
2.
Untreated materials, water, or chemicals are harmful and have not been made safe.
...the dumping of nuclear waste and ~ sewage.
ADJ: usu ADJ n
3.
Untreated materials are in their natural or original state, often before being prepared for use in a particular process.
All the bedding is made of simple, ~ cotton...
In its ~ state the carbon fibre material is rather like cloth.
= raw
ADJ: usu ADJ n