でかい

Etymology
Found in during the.

Generally considered to be a variation from, from the emphasizing prefix and the adjective. The  states that the sound change of →  does not match the facts of the term's development. However, the →  sound shift is quite common in Japanese, and the question may hinge on which form appeared first,  or. If evolved from  instead of the other way around, the do + ikai derivation would not explain the geminate  in. The  suggests an alternative derivation of + : * → * → * →  →.

Also said to be the adjective form of, from , transitive of. However, the semantic development required for this is improbable, and this is more likely a folk etymology.

Adjective

 * 1)  huge, big, severe, intense