Easily broken or destroyed, and thus often of subtle or intricate structure. / (UK) Feeling weak or easily disturbed as a result of illness. / (UK) Thin-skinned or oversensitive.

plural of phiomorph

Initialism of industrial hygiene. / Initialism of idiopathic hypersomnia.

(inorganic chemistry, mineralogy) A chemical compound with a formula containing four silicon atoms and twelve oxygen atoms (Si₄O₁₂)