申す is read as もうす (mousu) and means to do.
もうす
mousu
もうしつかわす
to write to
もうしこみ
application
しんこく
report
もうしあげる
to do
もうしでる
to offer
もうしこむ
to apply for
もうしいれ
proposal
もうしたて
statement
もうしで
もうしあわせ
mutual agreement
もうしいれる
to propose
さる
7th month of the lunar calendar