Extended Strong's Greek Lexicon (Abbott-Smith based)
citron
Usage: θύινος (usually θύϊνος, as Rec.), -η, -ον (θυία, θύα, an African aromatic tree, with ornamentally veined wood of varying colour, = Lat. citrinus), [in Sm.: 3Ki.10:11 (אַלְמֻגִּים)* ;] thyme: ξύλον, Rev.18:12 (Diosc.).† (AS)