1) To make clean, to keep clear of rubbish or any unwanted matter.
It is an older word than ‘clean’ and occurs in early coal-mining contexts: 1486 with due purging and clensinge of the seid myne, Cortworth
1750 to cleanse and repair the level formerly driven by Mr Monckton, Elsecar. It also had the special meaning of ‘to clear’ in some springwood leases: 1520 libertye to stube upe and clense certain growndes, Bishopside
1684 the brush and underwood taken out … all sprung and cleansed, Tong
1704 to be fallen and pilled … within seven years from hence … and Cleansed … as the same hath been formerly yearly fallen and done, Bradley
1719 all the Cordwood and charcoale … fully cleansed before 29 September 1722, North Bierley. The acreage of woods was often ‘by estimation’, and cleansing allowed more accurate measurements to be taken. In carpentry it was a process in the preparation of timber: c.1520 Johanni Henryson sawyng et clensyng bordes pro floyyre [floor] per v dies et di. 2s 9d, Ripon.