Formalin (noun)

A clear, colorless, aqueous solution of formaldehyde, used as a disinfectant and preservative, especially for biological specimens.

Origin:

From the phrase "formaldehyde" which is the chemical compound from which formalin is derived.

Examples:

1. He used formalin to preserve the specimen of the butterfly.
2. The chemical smell of formalin was overwhelming in the laboratory.
3. The formalin was used to sterilize the equipment before the surgery.
4. The fish was stored in formalin before it was dissected in class.
5. The formalin solution was too strong and damaged the tissue samples.