Green’s Dictionary of Slang

an ill-mannered lout, one who lacks gentlemanly breeding; also attrib.

1568		Institucion of a Gentleman 13: If a Gentleman haue in hym any humble behauour, then Roysters do cal suche one by the name of a Loute, a Clynchpope, or one that knoweth no facions.
1577		J. Northbrooke Treatise against Dicing (1843) 8: [as cit. 1568].
1584		Three Ladies of London II: What a clinchpoope drudge is this – I can forbeare him no more.
1589		W. Warner Albion’s England Bk 6 xxxi 136: Not far of was a Loute With neare a hansome rag [...] more il-fac’st, and like Clenchpoope looke and lim.