plough iron
/ˈplaʊ ˌʌɪən/(US plow iron)
noun
Any iron part of a plough; specifically (in plural) the coulter and share taken together.
Origin
Late Middle English. From plough + iron. Compare Middle Dutch ploechiser (Dutch ploegijzer), Middle Low German plōchīsern, plōchīseren, Middle High German phluocīsen, phluocīser (German Pflugeisen), Old Icelandic plóg-járn, Old Swedish ploghiärn (Swedish plogjärn), Old Danish plogjaern, plowjaern (Danish plovjaern, plovjern).