Difference between Unpleasant and Caustic

UNPLEASANT vs CAUSTIC: NOUN

The enveloping surface formed by light rays reflecting or refracting from a curved surface, especially one with spherical aberration.
A hydroxide of a light metal.
A caustic material or substance.
The envelope of reflected or refracted rays of light for a given surface or object.
Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic.
Any chemical substance that burns or destroys living tissue
Caustic soda
A caustic curve or caustic surface.

Of a substance, especially a strong acid; capable of destroying or eating away by chemical action
Harsh or corrosive in tone
Sarcastic or cutting; biting.
Given to making caustic remarks.
Sharp, bitter, cutting, biting, sarcastic
A surface to which rays reflected or refracted by another surface are tangents. Caustic curves and surfaces are called catacaustic when formed by reflection, and diacaustic when formed by refraction.
Capable of destroying the texture of anything or eating away its substance by chemical action; burning; corrosive; searing.
Severe; satirical; sharp.
A curve to which the ray of light, reflected or refracted by another curve, are tangents, the reflecting or refracting curve and the luminous point being in one plane.
See under Lime.
The solid hydroxides potash, KOH, and soda, NaOH, or solutions of the same.
Nitrate of silver, lunar caustic.

The curved surface to which all the rays of a conical pencil of light entering a refractive medium are tangential.
Capable of burning, corroding, or destroying the tissue of animal substances. See causticity.
Figuratively, severely critical or sarcastic; cutting: as, a caustic remark.
The envelope of light rays reflected or refracted by a curved surface or object

Unhappy, Caustic, Acrid, Mortifying, Bitter, Unlovely, Grim, Obnoxious, Hellish, Harsh, Dreadful, Awful, Embarrassing, Nasty, Painful

Acerb, Erosive, Destructive, Blistering, Sulphurous, Unpleasant, Virulent, Acid, Bitter, Sulfurous, Acrid, Venomous, Corrosive, Vitriolic, Acerbic

Unhappy, Caustic, Acrid, Mortifying, Bitter, Unlovely, Grim, Obnoxious, Hellish, Harsh, Dreadful, Awful, Embarrassing, Nasty, Painful

Acerb, Erosive, Destructive, Blistering, Sulphurous, Unpleasant, Virulent, Acid, Bitter, Sulfurous, Acrid, Venomous, Corrosive, Vitriolic, Acerbic

II Stonedll driving is unpleasant, say marijuana smokers.
At its worst, it is painful and unpleasant.
And that presents a number of unpleasant symptoms.
Someone that is old, wrinkly and generally unpleasant.
Being set up for failure is incredibly unpleasant.
It left such a sticky and unpleasant film.
You meet your Tour MENTOR andthe UNPLEASANT STRANGER.
In general, pictures of death are less unpleasant, elicit less arousal, and have greater dominance than unpleasant pictures.
Similarly, the spiciness of black pepper is unpleasant to some people so it might also be unpleasant for rats.
Because punishment is unpleasant, it can also trigger aggression just like other unpleasant events.

These could be toxic, corrosive, caustic or flammable.
My favorite are the dust and caustic caverns.
Do not use caustic drain openers and cleaners.
Celerier M, Extensive abdominal surgery after caustic ingestion.
What are the health effects of caustic soda?
He was also famous for his caustic wit.
The bulk bag will be lifted, by the caustic hoist, to the bulk bag splitter mounted above the caustic mixing tank.
The cocoanut oil is first saponified with the caustic soda and then the caustic potash is added with constant stirring.
The superferritics are resistant in caustic evaporators, but their performance is probably strongly influenced by oxidizing contaminants in the caustic.
There is an older domestic conversion which uses a mixture of molten caustic soda and caustic potash.