ancillary /an-silˈə-ri or anˈsi-lə-ri/

1. Auxiliary
2. Supplementary
3. Subsidiary
4. Subordinate
5. (of computer equipment) additional in any way, not a necessary part of the computing process
6. Subserving
7. Ministering

An ancillary thing

• expertises
• expertising
• expertize
• expertized
• expertizes
• expertizing
• expertly
• expertness
• expertnesses
• experts
• expert system
• expert systems
• expiable
• expiate
• expiated
• expiates
• expiating
• expiation
• expiations
• expiator
• expiators
• expiatory
• expirable
• expirant
• expirants