In "The Star-Spangled Banner," "fitfully" means which of the following: scorning, irregularly, sparked, greeted, terrifying?

In the poem "The Star-Spangled Banner" the use of the word
fitfully is in the lines:

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On the shore dimly seen through the mists of the deep,

Where the foe's haughty host in dread silence reposes,
What is that which
the breeze, o'er the towering steep,
As it
fitfully blows, now conceals, now
discloses?

On the shore the enemy is
difficult to see due to the mist. They become visible when the mist is lifted for brief periods
of time in an irregular manner by the breeze.

The definition of the
word fitfully which is used as an adjective is "coming, appearing, acting, etc., in fits or by
spells; recurring irregularly."

Fitfully means
irregularly. None of the other options scorning, sparked, greeted or terrifying have the same
meaning as the word.