IPA: /nɒnˈɪreɪdiˌeɪtɪd/
KK: /nɑnˈɪreɪdiˌeɪtɪd/
Describing something that has not been exposed to radiation.
The nonirradiated samples were used for comparison in the experiment.
Nonirradiated → It is formed from "non-" (meaning not) and "irradiated" (from Latin "irradiatus", meaning to shine upon or to emit rays). The word "nonirradiated" means not exposed to radiation or not having been irradiated.
Think of 'non-' meaning not, and 'irradiated' meaning having been exposed to rays or radiation. So, nonirradiated describes something that has not been exposed to those rays.