Accompanying as a subordinate; additional; accessory; especially, uniting in, or contributing to, a crime, but not as chief actor. See accessory.
Someone who accedes to some act, now especially a crime; one who contributes as an assistant or instigator to the commission of an offense.
Acting to supplement.
Lacking a regular schedule (as in a supplemental airline).
Appending.
Something that supplements or adds to.
A requisition or article of legislation that provides additional funding for a program.