aleatory (en)

(adjective) depending on an uncertain event or contingency as to both profit and loss / (adjective) relating to luck and especially to bad luck

ambit (en)

(noun) the scope, extent, or bounds of something

liminal (en)

ambiguous; occupying a position at, or on both sides of, a boundary or threshold

penumbra (en)

the partially shaded outer region of the shadow cast by an opaque object

penumbra (en)

the partially shaded outer region of the shadow cast by an opaque object