1 to block up (a road, pipe etc)

2 to stop up (a hole)

3 (fig.) (of a person) choked up with anxiety or stress

4 wall (literary)

5 (classifier for walls)

1 traffic jam

2 (of traffic) to get congested

1 to protect

2 to defend

3 to guard against

4 to prevent

1 to prevent

2 to guard against

3 to take precautions

1 to prevent

2 to take precautions against

3 to protect

4 to guard against

5 precautionary

6 prophylactic

1 to guard against the unexpected (idiom); just in case

2 prepared for any eventualities

1 frugality in order to prevent destitution (idiom)

1 A small hole not plugged will make you suffer a big hole (idiom); A stitch in time saves nine.

1 a small hole not plugged will give you grief when it gets bigger (idiom)

2 a stitch in time saves nine

1 If you don't plug the small hole, the big hole will be hard to repair (idiom); A stitch in time saves nine.