Rumex obtusifolius, where it may be derived from "Bitter Dock" but is also associated with the historic use of broad-leaf dock to wrap and preserve butter.
Dixon of Dock Green | Albert Dock | Tyne Dock | Peanut Butter Wolf | Royal Victoria Dock | Reese's Peanut Butter Cups | Hot Butter | Victoria Dock | Tilbury (the dock town, founded from c.1883) | Stanley Dock | Rotterdam-class amphibious transport dock | Pembroke Dock | London Dock Strike of 1889 | Immingham Dock | cocoa butter | butter churn | butter | Albert Dock Seamen's Hospital | We Butter The Bread With Butter | Victoria Dock (Melbourne) | Tyne Dock Metro station | Sportivo Dock Sud | Sittin' on the Dock of the Bay | (Sittin' on) the Dock of the Bay | Royal Portbury Dock | Royal Albert Dock | Regent's Canal Dock | Prairie dock | Peter Pan (peanut butter) | Peanut Butter Wolf Presents Stones Throw: Ten Years |