irreducible (adj.)

• an
• any
• atomic
• austere
• bare
• basic
• chaste
• deep-seated
• either
• elementary
• esoteric
• essential
• exclusive
• fundamental
• homely
• homespun
• homogeneous
• immanent
• implanted
• implicit
• inalienable
• indicated
• indispensable
• individual
• indivisible
• indwelling
• inextricable
• ingrained
• inherent
• inner
• integral
• internal
• intrinsic
• inward
• inwrought
• irreplaceable
• lone
• mere
• monistic
• monolithic
• necessary
• needed
• needful
• one
• plain
• prerequisite
• primal
• primary
• private
• pure
• required
• requisite
• resident
• secret
• severe
• simple
• single
• singular
• sole
• solid
• solitary
• spare
• stark
• subjective
• unadorned
• unalienable
• unanalyzable
• unchallengeable
• uncluttered
• undifferentiated
• undivided
• uniform
• unique
• unitary
• unquestionable
• unsolvable
• vital
• wanted
• whole