contention (n.)

• altercation
• antagonism
• antipathy
• antithesis
• apologetics
• apologia
• apology
• argument
• argumentation
• belligerence
• belligerent
• bicker
• bickering
• brawl
• broil
• carping
• casuistry
• challenge
• clash
• collision
• conflict
• confrontation
• contestation
• contradiction
• contrariety
• contrary
• contrast
• contravention
• controversy
• counteraction
• crosscurrent
• crossing
• defense
• denial
• difference
• discord
• discordance
• disharmony
• disputation
• dispute
• dissension
• dissent
• dissidence
• disunity
• embroilment
• enmity
• faultfinding
• feud
• fight
• fracas
• friction
• froward
• fuss
• hassle
• hate
• hatred
• hostility
• hubbub
• hurrah
• imbroglio
• incompatibility
• inharmoniousness
• jangle
• jar
• litigation
• logomachy
• malevolence
• malice
• malignity
• militant
• mischief
• negation
• opposition
• polarity
• polarization
• polemic
• polemics
• quarrel
• quarrelsomeness
• rebuttal
• refusal
• rejection
• repugnance
• resistance
• rhubarb
• rub
• rumpus
• set-to
• snarl
• spat
• spite
• spitefulness
• squabble
• strife
• tension
• tiff
• traversal
• tussle
• undercurrent
• unpleasantness
• variance
• vendetta
• words
• wrangle
• wrangling