Correct

千古

/ qiāngǔ / 
Strokes

Definition

for all eternity/throughout all ages

Example

As a Noun

ages; long period of time

1
Qiāngǔyīdì
千古一帝

outstanding emperor of the millennium

2
Qiāngǔ
千古
chuánsòng
传诵

be read through all ages

As a Verb

eternity ［used in an elegiac couplet or on wreaths dedicated to the dead］

3
Mǒumǒu
某某
xiānsheng
先生
qiāngǔ
千古
  
!

Eternal peace/repose/rest to Mr so-and-so!