ulterior (adj.)

• accessory
• additional
• alien
• ambiguous
• ancillary
• another
• arcane
• auxiliary
• barbarian
• barbaric
• barbarous
• buried
• cabalistic
• censored
• classified
• close
• closed
• collateral
• concealed
• contributory
• covert
• cryptic
• dark
• enigmatic
• equivocal
• esoteric
• exotic
• exterior
• external
• extra
• extraneous
• extraterrestrial
• extrinsic
• farther
• foreign
• foreign-born
• fresh
• further
• guarded
• hermetic
• hidden
• hush-hush
• intrusive
• latent
• more
• mysterious
• new
• obscure
• occult
• other
• outlandish
• outside
• personal
• plus
• private
• privy
• remote
• restricted
• secret
• smothered
• spare
• stifled
• strange
• supernumerary
• supplemental
• supplementary
• suppressed
• surplus
• surreptitious
• underhanded
• underlying
• undisclosed
• unearthly
• unexpressed
• unrevealed
• unspoken
• untellable
• untold
• unutterable
• unuttered
• yon
• yonder