unpleasantness (n.)

• badness
• clash
• conflict
• contention
• discord
• discordance
• disharmony
• enmity
• evilness
• friction
• improperness
• inaccuracy
• inauspiciousness
• incompatibility
• inexpedience
• inferiority
• inharmoniousness
• invalidity
• jangle
• jar
• malevolence
• mischief
• reprehensibility
• rub
• tension
• unfavorableness
• unhealthiness
• unkindness
• unskillfulness
• viciousness
• wickedness