accessoriness
/əkˈsɛs(ə)rɪnɪs/ /akˈsɛs(ə)rɪnɪs/noun
1The fact or condition of acceding to or aiding in a crime or misdeed; secondary involvement. Compare accessariness. Frequently with to, †unto.
2The quality or condition of being supplementary or subordinate; secondariness.
Origin
Mid 17th century; earliest use found in Vines's Treatise Lords-supper. From accessory + -ness.