WHAT'S MISSING?

The last four blanks in each clue below can be filled in with a common four-letter word. The same word appears in each clue. Can you determine the four-letter word and the six new words?

I _ _ _ _ _

E _ _ _ _ _

PR _ _ _ _ _

DI _ _ _ _ _

CO _ _ _ _ _

PO _ _ _ _ _

HINT 1:

The four-letter word starts with T.

HINT 2:

The four-letter word ends with D.

Answer:

The word is TEND ....... INTEND / EXTEND / PRETEND / DISTEND / CONTEND / PORTEND