Synonyms for Tension (same or very similar meaning)
WordNet sense 1 (the physical condition of being stretched or strained):
tautness, tenseness, tensityWordNet sense 2 ((psychology) a state of mental or emotional strain or suspense):
stressWordNet sense 3 (feelings of hostility that are not manifest):
latent hostilityFrom the ODE community, based on WordNetadd/edit