“Robust” is an adjective that means full of strength and health. While “aggressive” and “energetic” might be characteristics of a “robust” person, they aren’t close synonyms. Of the answer choices, “healthy” has the closest meaning.

"Turgid" means "swollen" or congested. 

"Dissolved" means to be broken down into a liquid form.

"Shrunken" means became smaller.

"Succulent" means tender or juicy.

"Emaciated" means abnormally thin or weak.

"Potent" means "powerful" or having a big influence or effect. 

None of the other words are synonymous. Things that are "alcoholic" can certainly be potent, but "alcoholic" simply means containing alcohol. "Calming" means to make someone or something tranquil. "Poisonous" means capable of causing illness or death if taken into the body. To be "morbid" means to take an abnormal degree of interest in death and disease.

"Sweltering" is an adjective that typically refers to weather and means "uncomfortably hot."

"Windy" means breezy or the weather pattern of significant flow. "Stringent," typically referring to rules or requirements, means strict or firm. "Frigid" means very cold. "Boiling" means bringing liquid to the temperature at which it changes from liquid to gas and evaporates.

"Oblong" is an adjective that means having a long shape, for example an oval is an oblong shape.

"Rigid" means inflexible or resistant to change. "Flat" means smooth, or a surface that doesn't change its elevation. When describing a human, "flat" means dull or without emotion. "Curved", when referring to a line, means not perfectly straight. "Stout" means stocky or solidly built.

"Decrepit" and "dilapidated" both mean old, worn out, or falling apart due to neglect. Someone who is skeptical has doubts or is unconvinced, and someone who is suspicious also has doubts or distrust. "Pessimistic," the opposite of optimistic, means having a negative outlook on life, and "scandalous" means disgraceful or outrageous.

"Nondescript" describes something that lacks distinct or interesting characteristics, something that is not remarkable in any way. Something silent makes no noise, something functional works or functions correctly, and something unusual is strange or out of the ordinary. "Magnificent" is a word meaning beautiful, excellent, or striking.

"Damp" means slightly wet or moist. Deep means the opposite of shallow, and "nocturnal" means taking place at night. "Earthy" is a word that can describe soil or hearty, strong people. "Dismal" means depressing and gloomy.

"Gauzy," which is often used to describe veil-like fabric, means thin and translucent. "Fashionable" means stylish and is often used to describe people or clothing. "Showy" means having a striking or flashy appearance, often drawing too much attention to itself. Someone who is "talkative" is very chatty and talks frequently.

"Vacant" means empty or unoccupied. "Free" means uncontrolled or unrestrained by others; "cautious" means wary or careful. "Grim" means depressing or forbidding, and often describes situations or people's expressions. "Obnoxious" means offensive and annoying.