the.com/grandkid

means The child of your child — the next generation down, and usually the softest spot in a grandparent's heart.

from Simply 'grand' (from Latin grandis, 'great/large,' used in family terms to mark a generation's remove, as in grandmother, grandfather) plus 'kid,' the casual English word for child, itself possibly from the Old Norse word for young goat — kid — playfully extended to human offspring by the 1600s. 'Grandkid' is the informal, modern shortcut, popping up once 'grandchild' felt a touch too stiff for everyday cooing.