1. having a valence of five; capable of combining with five atoms of hydrogen or their equivalent
Usage: chemistry; also called quinquevalent
2. of or relating to a vaccine that protects against five different strains or types of a disease
Usage: medicine; immunology

Examples

• Phosphorus is pentavalent in phosphoric acid.
• The pentavalent vaccine protects against five serotypes of the virus.
• Arsenic can exist in both trivalent and pentavalent forms.
• The pentavalent rotavirus vaccine has significantly reduced childhood gastroenteritis.
• In organic chemistry, carbon is typically tetravalent, while nitrogen can be trivalent or pentavalent in certain compounds.