by the thousands

by the thousands

In huge quantities, presumably numbering several thousand. When the potato famine hit Ireland, the Irish began emigrating—especially to America—by the thousands.
See also: thousand
References in classic literature ?
He sang it in a still, small voice, but, line after line, his song was caught up by the thousands who stood on the slopes above, and thundered to the heavens till the mountains shook with its sound.