austere
adj.simple, plain, and not decorated. It can also describe a person who lives a very strict and serious life without many comforts.
adj.characterised by simplicity, plainness, and a lack of ornamentation; also describes a lifestyle or person marked by strictness and a lack of indulgence.
“The room has an austere, modern look with no extra furniture.”
“The monk lived an austere life, spending most of his time in silent prayer and manual labor.”
“The architect designed the library with an austere aesthetic, using raw concrete and steel to create a space that felt both functional and deeply contemplative.”
Usage austere conditions
“There sits the studio, an austere black cube jutting into the countryside, guarded by a giant sculpture of a gorilla.”
“Olga, Tatiana, Maria and Anastasia grew up under surprisingly austere conditions imposed by their Victorian-minded mother.”
From Ancient Greek αὐστηρός (austērós, “bitter, harsh, astringent”), having the specific meaning “making the tongue dry” (originally used of fruits, wines), related to αὔω (aúō, “to singe”), αὖος (aûos, “dry”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.