1) The earliest OED examples of this occupational term are for 1784 and 1813 but it was well established in Holderness in the sixteenth century.
1569 Thomas Lynsay, Albroughe in Holderness, darie man
1572 Thomas Thwinge, Ottringham Marsh, darieman. In an Oubrough tithe dispute a witness named William Hodgson testified that in 1569 he hard saie ther was a deary man which occupied xx kyen and paid certen butter and chese to the monasterie
that is to Swine Priory. Local custom evidently outlived the Dissolution 1601 Robert Smith, Bowrehouse Hill, Paul, dairyman.