Question: Here is one sentence: As there was a lot of damage, we chose the heavy roller to flatten the pitch.
Here is another sentence: Flatten a road.
Does the flatten mean the same thing in the two sentences?

Answer: the same meaning

Question: Here is one sentence: We could do with a little more help around here.
Here is another sentence: We did 6 miles on our hike every day.
Does the do mean the same thing in the two sentences?

Answer: different meanings

Question: Here is one sentence: You were in the courtroom. What is your reaction?
Here is another sentence: A bad reaction to the medicine.
Does the reaction mean the same thing in the two sentences?

Answer: the same meaning

Question: Here is one sentence: Dissent to the laws of the country.
Here is another sentence: Several Republicans dissented.
Does the dissent mean the same thing in the two sentences?

Answer:
different meanings