words

cir·cu·late
–verb (used without object)
1. to move in a circle or circuit; move or pass through a circuit back to the starting point: Blood circulates throughout the body.
2. to pass from place to place, from person to person, etc.: She circulated among her guests.
3. to be distributed or sold, esp. over a wide area.
4. Library Science. (of books and other materials) to be available for borrowing by patrons of a library for a specified period of time.
–verb (used with object) 5. to cause to pass from place to place, person to person, etc.; disseminate; distribute: to circulate a rumor.
6. Library Science. to lend (books and other materials) to patrons of a library for a specified period of time.

shel·ter
–verb (used with object) 7. to be a shelter for; afford shelter to: The old barn sheltered him from the rain.
8. to provide with a shelter; place under cover.
9. to protect, as by shelter; take under one's protection: Parents should not try to shelter their children from normal childhood disappointments.
10. Finance. to invest (money) in a tax shelter.
–verb (used without object) 11. to take shelter; find a refuge: He sheltered in a barn.
12. Finance. to invest money in a tax shelter.

in·ter·act
-verb (used without object)
to act one upon another