1. (chemistry) a property of atoms or radicals
[…]nbsp;[…]nbsp;[…]nbsp;[…]nbsp;their combining power given in terms of the number of hydrogen atoms (or the equivalent)

[…]nbsp;[…]nbsp;[…]nbsp;[…]nbsp;Synonym: valency

2. (biology) a relative capacity to unite or react or interact as with antigens or a biological substrate

[…]nbsp;[…]nbsp;[…]nbsp;[…]nbsp;Synonym: valency