THAT IS
Credit: LA Times Crossword - Aug. 5, 2008
Verna Suit

The answers to the clues below will have something in common:

1. Frequent restaurant customer, perhaps
2. Sweatshirt feature
3. Touring band helper
4. First-year player
5. Golf score one under par
6. Dust Bowl migrant
7. Knitted cap
8. Soccer or hockey player
9. Military raid
10. Illegal bet taker

Answers:

1. FOODIE
2. HOODIE
3. ROADIE
4. ROOKIE
5. BIRDIE
6. OKIE
7. BEANIE
8. GOALIE
9. SORTIE
10. BOOKIE

[IE - i.e. - that is (id est)]