thousands; many thousands
Used to express a large, indefinite number in the thousands. Often carries a literary or emphatic tone compared to 数千.
Thousands of stars were shining in the night sky.
He repeated that practice thousands of times.
tens of millions; countless thousands
Compound of 幾 (iku, 'how many') + 千 (sen, 'thousand'). The exact historical derivation is straightforward.