adverb
just about to; on the verge of
Used before a verb to indicate that something is imminent or about to happen. Often followed by ~するところ or ~しそう.
See also: まさに
電車がまさに発車するところです。
The train is just about to depart.
彼はまさに泣き出しそうだった。
He was on the verge of tears.