lacking refinement or propriety, e.g.:
discourteous
vulgar; indecent
ignorant; unlearned
sudden and unpleasant; abrupt
a rude awakening
robust; vigorous
in rude health
in a rough or unfinished state
primitive; undeveloped
rudely adv
rudeness noun
rudery /ʹroohd(ə)ri/ noun
[Middle English via French from Latin rudis crude, raw]