The word "incidental" means something that happens by chance or is not planned or expected. It can refer to something that is related, but not the main focus or purpose. Full definition
If you're looking for a little more flexibility, consider a rewards credit card with transferable points that also offers reimbursement for incidental airline charges. (rewardexpert.com)
However, the vast amount of data and inevitable discovery of incidental findings require novel analytic approaches. (completegenomics.com)
The card has a $ 100 per calendar year airline incidental fee credit, which offsets the annual fee. (millionmilesecrets.com)