fin ‧ ger ‧ tip /ˈfɪŋɡəˌtɪp $ -ɡər-/ BrE AmE noun [countable]
1 . the end of your finger that is furthest away from your hand:
She touched his cheek gently with her fingertips.
2 . have something at your/their etc fingertips to have knowledge or information ready and available to use very easily:
We have all the facts and figures at our fingertips.
3 . to his/her fingertips British English in all ways; completely:
She’s British to her fingertips.