四重 is read as しじゅう (shijuu) and means fourfold.
しじゅう
shijuu
しじゅうそう
instrumental quartet
しじゅうしょう
vocal quartet
しじゅうきん
four grave prohibitions (killing, theft, adultery, and deceit)
よんじゅうく
four-fold hardship
げんがくしじゅうそうだん
string quartet
しほう
four sides (of a square)
よつぎり
photograph size 254mm x 305 mm
しで
hornbeam (deciduous tree in the birch family)
よんだいたいかい
the four most important tournaments in a particular sport
しじゅうはって
every trick in the book
しぶん
divide into four pieces
しこくちほう
Shikoku region (incl. Tokushima, Kagawa, Ehime and Kochi prefectures)