unbegun
That had no beginning; always existent.
Thou knowest not how came ye, hence callest thyself unbegotten; certainly knowest not thy beginning, hence callest thyself unbegun.
Which has not yet been begun; unstarted.
Where it comes from
From Middle English unbegunne, unbegunnon, unbigonne, unbigunnen, unbigunnon, unnbigunnenn, from Old English unbegunnen; equivalent to un- + begun.
Adapted from the Wiktionary entry unbegun (CC BY-SA 4.0).