arbitrary (adj.)

• absolute
• absolutist
• absolutistic
• aristocratic
• arrogant
• autarchic
• authoritarian
• authoritative
• autocratic
• autonomous
• bossy
• capricious
• careless
• chance
• chancy
• cranky
• crotchety
• despotic
• dictatorial
• discretional
• discretionary
• dogmatic
• domineering
• doubtful
• elective
• erratic
• fanciful
• fantastic
• feudal
• flaky
• freakish
• free
• gratuitous
• harebrained
• heedless
• high-handed
• iffy
• imperative
• imperial
• imperious
• impetuous
• inadvertent
• inconsiderate
• inconsistent
• independent
• indiscreet
• irrational
• kinky
• kooky
• lordly
• maggoty
• magisterial
• masterful
• moody
• motiveless
• nonmandatory
• notional
• oppressive
• optional
• oracular
• overbearing
• peremptory
• petulant
• precipitate
• quirky
• random
• rash
• reasonless
• repressive
• screwball
• self-acting
• severe
• spontaneous
• strict
• subjective
• summary
• suppressive
• temperamental
• thoughtless
• tyrannical
• tyrannous
• unasked
• uncalled-for
• uncertain
• uncoerced
• uncompromising
• unconstrained
• undisciplined
• unforced
• unguarded
• uninfluenced
• uninvited
• unpredictable
• unprompted
• unreasonable
• unreasoning
• unrequested
• unrestrained
• unruly
• unsolicited
• unsought
• unthinking
• unthoughtful
• vagrant
• varying
• voluntary
• volunteer
• wanton
• wayward
• whimsical
• wild
• willful
• zany