hold something up—
1. support smth. physically; bear the weight of smth.:
- We couldn’t hold up the fence, and it finally fell over.
2. (of prices, etc.) cause to remain high:
- Efforts were made to hold up the price by again cutting production.
3. stop or delay smth.; make smth. late:
- A heavy storm in Boston held up our plane.
4. stop a car, etc. in order to rob:
- The thieves held up a van carrying a factory payroll.
Note:
a) The expression does not correlate in meaning with the phrase uphold something—
1. (of a law, etc.) support and maintain smth.:
- We will loyally uphold the principles of the United Nations.
2. (of a verdict, decision, etc.) confirm or endorse:
- His court conviction was upheld on appeal.
b) The expression does not correlate in meaning with the phrase hold up on something—delay doing smth.:
- I have to hold up on my reading because I broke my glasses.
keep something up—
1. = hold something up 1:
- My husband lost so much weight that he has to wear a belt to keep his trousers up.
2. = hold something up 2:
- Since it is “back-toschool” time, I expect lots of students are buying laptops, and are keeping the prices up.
3. keep smth. in good condition; maintain smth.:
- How do you keep up a house as large as this without help?
4. continue smth.:
- Jane will have to keep up her piano practice if she wants to be a professional performer.