vex, oppress, Irish
claoidhim, Old Irish
clóim, Welsh
cluddio, overwhelm,
*cloid; Indo-European
klei, incline, as in
claon, q.v. Windisch and Stokes refer it to
*cloviô, root
qlov,
qlav,
qlu, shut in, Latin
claudo, close,
claudus, lame, Greek
$$G kleís,
$$G kleidós, key.