noun, noun which may take the genitive case particle 'no'
the one before last; two generations previous
Refers to the person or thing two positions back in a generational or sequential context, such as a company president, family head, or title holder. Often used with 社長, 会長, 当主, etc.
先々代の社長が築いた方針を今も守っている。
We still follow the policies established by the president two generations ago.
この茶碗は先々
This tea bowl is a family heirloom passed down from two generations back.
Refers to the immediate previous generation or predecessor, while 先々代 goes one step further back.
The same word; included for reading clarity.
Compound of 先 (previous) reduplicated with the iteration mark 々 and 代 (generation/era). The reading せんせんだい is a straightforward combination of the on'yomi readings.