اصَّاعدَ في يصَّاعد، فهو مُصَّاعِد، والمفعول مُصَّاعَدٌ فيه

تصاعد، مضى فيه على مشقَّة، تكلّف صعودَه.

🇬🇧 Translation:

Ascended, went through it with difficulty, took upon himself its ascent (To climb with difficulty).