AtD translation: a white horse borne against the sky

[Mike Jing]

P297.5-10   The longer he stayed in this town, the less he was finding out.
The point of diminishing returns was fast approaching. Yet now, as the
trail ascended, as snowlines drew nearer and the wind became sovereign, he
found himself waiting for some split-second flare out there at the edges of
what he could see, a white horse borne against the sky, a black rush of
hair streaming unruly as the smoke that marbles the flames of Perdition.

What does the word "borne" mean here? (I do know it's the past participle
of "bear".)

According to the OED:

bear, v.1

Main senses: I. to carry; II. to sustain; III. to thrust, press; IV. to
bring forth.

In which sense is it used here?