The One who moves things forward. The One who grants advancement.
The One who expedites things. The One who advances or promotes.
From the root q-d-m which has the following classical Arabic connotations:
to precede, to come before
to head, to lead
to offer, to bring forward
to make foremost, to put at the front
to advance, to promote
to exist without beginning
The name Muqaddim is not specifically used as a Beautiful Name in the Qur'ān.
Wallahu ta’alaa ‘alem.
And Allah knows Best.