/up"thrust'/ , n.
1. a thrust in an upward direction.
2. a sudden and forceful upward movement, as of a nation's economy or the stock market: Market observers are hoping the upthrust can be sustained.
3. Geol. an upheaval.
v.i.
4. to thrust upward: Frost caused the ground to upthrust.
[ 1840-50; UP- + THRUST ]