STUMPERS XCVI

When the blanks are filled in to complete the partial words below, the three complete words will share a very, very unusual property. What are the three words and what is their distinguishing characteristic?

_ _ _ ORM
_ _ _ ACK
_ _ _ RDY

HINT:
It has to do with the alphabet.

Answer:

The words are:

DEFORM
HIJACK
STURDY

Each word begins with three consecutive letters of the alphabet.