sticking point 
noun
An obstacle to progress towards an agreement or goal: safety issues have been a sticking point in the negotiations...
- The prisoners have become a major sticking point to progress on the US-backed road map peace plan.
- It affords a temporary sticking point in the forward progress of evolution…
- Start the advanced routine only when you hit a sticking point in your general progress.
- horde
- Hordern, Sir Michael
- horehound
- horewood
- Horgan, Paul
- horizon
- horizontal
- horizontal bar
- horizontal gene transfer
- horizontality
- horizontally
- horizontal pendulum
- horizontal stabilizer
- Horkheimer, Max
- Horlicks
- Horlivka
- hormesis
- hormonal
- hormonally
- hormonal replacement
- hormone
- hormone replacement
- hormone replacement therapy
- hormone therapy
- hormone treatment