What is the meaning of てさえも?


These are lyrics from a song called 秘蜜～黒の誓い～

[code]

    地の底へ堕ちてさえも
    誓いの楔を絡め合って
    許されない罪を抱えていく
    
[/code]

The てさえも sounds a lot like a concession as in ても, but I could not find any
grammar explanation about that use. I'd like to know if I am correct and if
that is a common use.




Yes, てさえも/でさえも is a stronger version of ても/でも. While ても/でも does not necessary
have to be translated using "even", てさえも/でさえも has a strong sense of "even".

  * 1時間読んでも分からなかった。  
I did not understand (even) after reading it for an hour.

  * 1時間読んでさえも分からなかった。  
I did not understand EVEN after reading it for an hour.

  * 知らなくても大丈夫です。  
It's fine if you don't know it.

  * (見なくていいどころか)知らなくてさえも大丈夫です。  
(Not only do you not have to watch it) It's fine even if you don't know it.




Yes, てさえも/でさえも is a stronger version of ても/でも. While ても/でも does not necessary
have to be translated using "even", てさえも/でさえも has a strong sense of "even".

  * 1時間読んでも分からなかった。  
I did not understand (even) after reading it for an hour.

  * 1時間読んでさえも分からなかった。  
I did not understand EVEN after reading it for an hour.

  * 知らなくても大丈夫です。  
It's fine if you don't know it.

  * (見なくていいどころか)知らなくてさえも大丈夫です。  
(Not only do you not have to watch it) It's fine even if you don't know it.

