Fixative (noun)

1. A substance used to preserve or fix the position of a specimen or artwork.
2. A substance that preserves a biological specimen by preventing the breakdown of cellular structures.

Origin:

Mid 19th century: from french fixatif, -ive or from fixer "to fix".

Examples:

1. The artist used a fixative spray to keep the charcoal drawing in place.
2. The fixative was used to preserve the specimen for further study.
3. Fixative solution was applied to preserve the tissue samples.
4. The fixative was used to keep the fragrance from evaporating.
5. The fixative was used to keep the hair in place during the photo shoot.