Wiktionary
tilaka
n. (alternative form of tilak English)
Wikipedia
Tilaka
In Hinduism, the Tilaka ( Hindi: तिलक) is a mark worn usually on the forehead, sometimes other parts of the body such as neck, hand or chest. Tilaka may be worn on a daily basis or for rites of passage or special religious occasions only, depending on regional customs.
The term also refers to the South Asian ritual of marking someone's forehead with a fragrant paste, such as of sandalwood or vermilion, as a welcome and expression of honor when they arrive.