Word Summary
hyalos: a clear transparent stone, glass
Original Word: ὕαλος
Transliteration: hyalos
Phonetic Spelling: (hoo'-al-os)
Part of Speech: Noun, Masculine
Short Definition: a clear transparent stone, glass
Meaning: a clear transparent stone, glass
Strong's Concordance

Perhaps from the same as huetos (as being transparent like rain); glass -- glass.

see GREEK huetos

Thayer's Greek Lexicon
STRONGS NT 5194: ὕαλος

ὕαλος, ὑαλου, (probably allied with ὑει, ὑετός (which see); hence, 'rain-drop', Curtius, 9604; Vanicek, p. 1046; but others make it of Egyptian origin (cf. Liddell and Scott, under the word)), from Herodotus ((3, 24) who writes ὕελος; (cf. Winer's Grammar, 22)) down;

1. any stone transparent like glass.

2. glass: Revelation 21:18, 21.