1. Toward the source or against the current
   - upriver

1. In the direction against a stream's current 
2. In the direction towards the source of a signal; at a higher level
   "The messages are transmitted to dendrites by upstream neurons via synapses"

Antonym: downstream

Encyclopedia: Upstream

• Hellenism
• Hellenist
• Hellenistic
• Hellenistical
• Hellenize
• heller
• helleri
• Hellespont
• hellfire
• hellgrammiate
• hellhole
• hellhound
• hellion
• hellish
• hellishly
• Hellman
• hello
• helluva
• helm
• helmet
• helmet orchid
• helmet-shaped
• helmeted
• helmetflower
• Helmholtz