Shadowy means full of dark patches, or mysterious and little known. A shadowy corner, a shadowy figure, a shadowy organisation.
The figurative sense is much the commoner in reporting, where a shadowy group is one nobody can name the members of. A shadowy figure is the standard phrase in every witness statement.
1adjectiveshadowyFull of dark patches, or mysterious and little known.
“The old house had shadowy corners where the lamplight didn't reach.”
shadowy is a quality.
From shadow plus -y, with shadow from Old English sceadu, shade.
Middle English
schadwy
English, today
shadowy
From Middle English schadwy, schadowy, equivalent to shadow + -y.
Etymology from Wiktionary, CC BY-SA