'Preservative' definitions:

Definition of 'preservative'

From: WordNet
adjective
Tending or having the power to preserve; "timbers should be treated with a preservative substance"
noun
A chemical compound that is added to protect against decay or decomposition

Definition of 'Preservative'

From: GCIDE
  • Preservative \Pre*serv"a*tive\, a. [Cf. F. pr['e]servatif.] Having the power or quality of preserving; tending to preserve, or to keep from injury, decay, etc. [1913 Webster]

Definition of 'Preservative'

From: GCIDE
  • Preservative \Pre*serv"a*tive\, n. That which preserves, or has the power of preserving; a presevative agent. [1913 Webster]
  • To wear tablets as preservatives against the plague. --Bacon. [1913 Webster]