highlighter
Concise Oxford English Dictionary © 2008 Oxford University Press:
highlighter/ˈhʌɪlʌɪtə(r)/
▶noun
- 1 a broad marker pen used to overlay transparent fluorescent colour on text or a part of an illustration.
- 2 a cosmetic that is lighter than the wearer's foundation or skin, used to emphasize the cheekbones or other features.
'highlighter' also found in these Oxford entries:

