"Vacillate" means to be indecisive or waver between options. The opposite would be "conclude," which means to come to a decision or finish a thought or process.

Opposite words: Proceed, Advance, Decide, Conclude. 

"Dilate" means to become wider or expand. The opposite would be "narrow," which refers to making something smaller or more constricted.

Opposite words: Abridge, Abbreviate, Curtail, Dwindle, Narrow, 

"Repulsion" is a feeling of intense dislike or disgust. The opposite would be "attraction," which refers to the feeling of being drawn toward something or someone.

Opposite words:  Propensity, Fondness, Relish, Attraction.

"Discordant" refers to things that are in disagreement or out of harmony. The opposite would be "harmonious," meaning in agreement or balance, especially in terms of sound or relationships.

Opposite words: Harmonious, Euphonious, Melodious, Sonorous, Mellifluent.

"Mutter" refers to speaking in a low, indistinct, or complaining voice, often in a feeble manner. The opposite would be "outspoken," which means speaking openly and honestly, without hesitation.

Opposite words: Whimper, Shout, Wine, Outspoken.

"Animosity" refers to strong hostility or hatred. The opposite would be "harmony," which means peaceful coexistence, agreement, or a lack of conflict.

Opposite words: Friendliness, Cordiality, Amity, Alliance.

"Bombastic" refers to speech or writing that is pompous, inflated, and full of unnecessary exaggeration. The opposite would be "unimpressive," which refers to something lacking in impact or significance.

Opposite words: Unadorned, Unrhetorical, Unimpressive. 

"Sterilize" means to make something free from germs or bacteria. The opposite would be "adulterate," meaning to contaminate or add harmful substances to something, especially food or drink.

Opposite words: Adulterate, Blend, Taint, Dilute.

"Inundate" means to overwhelm or flood with things or people. The opposite would be "Parched" or "dehydrate," which means to remove or reduce something, especially to a point where it becomes scarce or dry.

Opposite words: Drain, Dehydrate, Parched.

"Stolid" refers to someone who is calm, showing little emotion or responsiveness. The opposite would be "excitable," referring to someone who is easily excited or responsive.

Opposite words: Responsive, Interested, Exuberant, Excitable.