1) The pole or shaft of a cart or wain, a regional word listed by Wright.
In a list of attributive uses he wrote of ‘the arrangement on the collar of a shaft-horse to which the shafts are attached by chains
hames having chains on each side’. That seems to be the meaning in the following example: 1739 a pair of sill hames, Emley. Perhaps also here: 1667 Three coupe waines & two silld waines, North Bierley. However, ‘sills’ could also be the timber sections which formed the body of a wain.