unsittenadj.
Etymology: Previous versions of the OED give the stress as: unˈsitten.
the world > animals > animal body > general parts > sexual organs and reproduction > [adjective] > relating to incubation > not sat upon
1611 A. Standish 15 If they finde many [wild ducks'] egges therein that be vnsitten.
This entry has not yet been fully updated (first published 1926; most recently modified version published online June 2019).