riv·er·weed 
(rĭvər-wēd′)
(rĭvər-wēd′)n.
Any of various aquatic plants of the family Podostemaceae, especially P. ceratophyllum of North America, which grows on rocks in rapidly flowing streams.
- inveterately
- inveterateness
- inviability
- inviable
- invidious
- invidiously
- in view of
- invigorate
- invigoratingly
- invigoration
- invigorator
- invincibility
- invincible
- invincibleness
- invincibly
- inviolability
- inviolable
- inviolableness
- inviolably
- inviolacy
- inviolate
- inviolately
- inviolateness
- in virtue of
- inviscid