diaphanous

1.

Of such fine texture as to allow light to pass through; translucent or transparent.

2.

Vague; insubstantial.

Quotes:

The curtains are thin, a diaphanous membrane thatcan't quite contain the light outside.

-- Eric Liu, The Accidental Asian

She needed more than diaphanous hope, more thanI could give her.

-- Tej Rae, "One Hand Extended", Washington Post ,August 12, 2001

This phantom wore many faces, but it always hadgolden hair, was enveloped in a diaphanous cloud,and floated airily before his mind's eye in a pleasingchaos of roses, peacocks, white ponies, and blueribbons.

-- Louisa May Alcott, Little Women

Origin:

Diaphanous ultimately derives from Greek diaphanes , "showing through," from diaphainein , "to showthrough, to be transparent," from dia- , "through" + phainein , "to show, to appear." It is related tophantom , something apparently sensed but having no physical reality.