ancillary
adjective
UK/ænˈsɪl.ᵊr.i/
US/ˈæn.sə.ler.i/
Definitions of ancillary adjective
providing support or help
The hospital relies on a large team of ancillary staff to keep operations running smoothly.
In the play, his role was ancillary, but his performance stole the show.
Besides direct aid, the charity also engages in ancillary activities.