A sight we no longer see: a group of sheaves or grain stood on end in a field. Also ‘to stook’, meaning to arrange (sheaves or grain) in a stook. It comes from Middle Low German stüke. I like Heaney’s adoption of this to describe warrior’s gathering their spears together.
‘They collected their spears in a seafarers’ stook, a stand of greyish tapering ash.’
Source: Seamus Heaney, Beowulf, p. 12