bare
plain
spare
unembellished
unornamented
untufted
Spartan
arcadian
ascetic
austere
bald
basic
blank
bucolic
candid
chaste
common
commonplace
direct
dry
dull
elementary
essential
frank
fundamental
genuine
homely
homespun
homogeneous
inartificial
indivisible
irreducible
lean
matter-of-fact
mere
monolithic
naked
native
natural
naturelike
neat
nude
of a piece
open
pastoral
plain-speaking
plain-spoken
primal
primary
prosaic
beige
colorless
drab
featureless
grimy
long-sleeved
loose-fitting
low-ceilinged
nondescript
spotless
stark
straightforward
unpretentious
unvarnished
utilitarian
windowless
adorned
forewarned
horned
mourned
scorned
warned