Esp. of a book: that achieves good sales or is sold in large numbers; that sells well. Cf. bestselling, adj.

Of a report, etc.: Widely current. Of a book: Widely circulated, popular. Obsolete.

That achieves better sales, or is sold in greater numbers, than anything or anyone else; that is a bestseller.

Of a book, record, etc.: that sells many copies. Cf. megaseller, n.