"Frigid" and "chilly" are synonyms adjectives describing the state of being cold. The other answer choices are synonymous with each other, and all refer to the state of being wet, but only "chilly" means the same thing as "frigid." Someone might be "frigid" because their clothes are "damp," but these adjectives are not in and of themselves synonymous.

The words "rigid" and "stiff" are synonymous adjectives describing the property of having tensile strength and being difficult to bend. The other answer choices do not have relevant meanings.

"Rustic" means "rural," or it can mean plain or crude. 

"Grisly" means gross, gruesome or horrifying.

"Slovenly" means disgusting, unkempt or dirty.

"Handsome" means physically attractive.

"Urban" means related to cities; it is the opposite of rural.

"Drab" means "dull" or bleak or rundown.

"Polished" means brightly shining or gleaming due to being cleaned with polish; it can also mean elegant or well-executed, when referring to an action.

"Flamboyant" means extravagant or flashy.

"Flimsy" means not sturdy; thin and insubstantial.

"Vibrant" means colorful, lively or vivid.

"Luminous" means "radiant" or glowing; shining with light.

"Flowery" means overly ornate, excessively fancy. Typically refers to unnecessarily fancy language.

"Outrageous" means barbaric, very bad or something that causes outrageous.

"Putrid" means rotten or stinky or contaminated.

"Dull" means not bright or shiny; drab or cloudy.

"Urbane" means "civilized," cosmopolitan or sophisticated.

"Lanky" means long-limbed, gangly or tall and thin.

"Unrealistic" means fanciful or not believable.

"Pristine" means pure, untouched by civilization, primeval.

"Stained" means dirty, impure or sullied.

"Sallow" means "unhealthy," pale, dull.

"Angelic" means like an angel; sweet, kind and typically beautiful.

"Phony" means false or bogus.

"Portly" means fat, round, overweight.

"Vigorous" means full of vigor, vivacious, energetic.

"Ajar" means "slightly open" or open a crack. For example, the door was ajar.

"Tidy" means neat, clean or orderly.

"Small" means not large in size, petite, or little. 

"Spectacular" means wonderful, impressive or something that catches the eye.

"Underneath" is a preposition that means below or under something.

'Dapper' means "classy," well-groomed or elegant.

"Gloomy" means dismal, depressing, sullen. Also has a meaning of dark or shadowed when describing landscapes.

"Sweltering" means extremely hot in temperature, scorching, humid.

"Drab" means bleak, colorless, or run-down in appearance.

"Ugly" means unattractive or unsightly. It can also describe anything that is unpleasant or dangerous.

The words "horrid" and "dreadful" are synonymous. They refer to something that inspires fear. The other answer choices do not have this meaning. Words like "homely," "honest," and "horticultural" may seem to have similar prefixes, but they have completely unrelated meanings.