The antonyms for the word "relaxedness" are tension, stiffness, rigidity, stress, and nervousness. These words represent opposite emotions or states of being to relaxation. Tension refers to a state of strain or tightness, while stiffness means inflexibility or unyieldingness. Rigidity implies a lack of flexibility or adaptability, and stress represents pressure, strain, or anxiety. Nervousness denotes a state of agitation or unease. The antonyms for relaxedness highlight the contrast between calmness and tension or anxiety, showing that different emotions can produce diametrically opposed reactions in people.