relatively low in position, rank, or order

less advanced in the scale of evolutionary development

lower organisms

denoting an earlier division of the named geological period or series

constituting the popular, more representative, and often, e.g. in Britain, more powerful branch of a legislative body consisting of two houses

the lower chamber

denotbe ing the southern part of a specified area

lower New York State

to reduce (something) in value, amount, degree, strength, or pitch, etc

to move down; to drop

= diminish (1)