Final answer:
The prefixes that mean 'under' are 'sub-' and 'hypo-'. 'Sub-' appears in words like 'subterranean', and 'hypo-' is used in terms like 'hypothermia' or in chemistry nomenclature like 'hypochlorite'.
Step-by-step explanation:
The prefixes that mean 'under' are sub- and hypo-. The prefix sub- can be found in words like subterranean, meaning beneath the earth, while hypo- is used in scientific terms such as hypothermia, which means below normal body temperature. Both prefixes imply a position lower than or less than something else. An example from chemistry further illustrates the meaning of hypo- in the naming of polyatomic ions; hypochlorite has fewer oxygen atoms than chlorite.