Derivational etymology which may have been designed as an alternative to Heraclides' derivation directly from δεινός. This derivation starts from δέος, from which it derives an adjective *δεεινός, a ghost form but a morphologically regular one (after κλέος, κλεεινός), and this derived form is the etymon of αἰνός before the contraction in δεινός. The etymologist applies the deletion of the initial consonant and the loss of the internal [e] of *δαεινός, which may betray a ioticizing pronunciation [dainos]. The two adjectives δεινός and αἰνός are synonyms and there is a remote formal resemblance, which allowed Greek etymologists to derive the rare, poetic word αἰνός from the usual one δεινός (see αἰνός / δεινός).