Alternative dialogue word you could use instead of the word…

Plain

As an adjective

Specifically meaning free from additions, additives, and/or embellishments

Absolute

Antiseptic

Au natural

Austere

Bald

Bare

Bleak

Clarified

Clean

Concentrated

Conservative

Denuded

Divested

Earthly

Elemental

Filtered

Fine

Forthright

Fresh

Full bodied

Homely

Honest

Inconspicuous

Modest

Muted

Naked

Natural

Neat

Plain vanilla

Pure

Purified

Quiet

Refined

Rendered

Severe

Simple

Sober

Spartan

Stark

Straight

Stripped

Strong

Subdued

Taintless

Toned

Toned down

Tried

Unadorned

Unadulterated

Unalloyed

Uncombined

Uncontaminated

Uncorrupt

Undecorated

Undefiled

Understated

Undiluted

Unembellished

Unobtrusive

Ornamented

Unpolluted

Unpretentious

Unsophisticated

Untainted

Varnished