This noun is a rare (and perhaps even questionable) aphetic form of apuiement.
s.
1support, prop:
(
MS: s.xiii
) Textor terestris eques es, qui duarum streparum adnitens (glosses: pouant / apuant) apodiamento (gloss: de le puement (l. de l'epuement?)) [equum] admittit assidue, exili tamen contentum diet
i 184.72 and ii 113.72
[puiement] (s.xiii)