The "Primary Dictionary of The English Language Philadelphia 1860" is a vocabulary book authored by Joseph E. Worcester, published by J. B. Lippincott and Co. This dictionary focuses on the English language and serves as a valuable reference for those interested in language studies. With a publication year of 1860, it provides a comprehensive collection of words and definitions relevant to the English language during that time period, making it a useful tool for historical language research and linguistic analysis.