上下[shàng xià]
词典high and low：到处；贵贱上下；上下。
词典上下什么意思
词典old and young：老老少少；上下；黄发垂髫。
词典from top to bottom：自上而下；上下；从上到下， 完全；上上下下。
词典up and down：上上下下；起落。
词典fluctuate：波动；涨落。
上下[shàng xià]
（职务、辈分上的高低） high and low; old and young:
例：举国上下
the whole nation;
全家上上下下都很高兴。
All members of the family, old and young, are very pleased.
（从上到下） from top to bottom; up and down:
例：这个水塔上下有50米。
The water tower is fifty metres high.
（从高到低或从低到高） go up and down:
例：摩天楼里有电梯，上下很方便。
With an elevator in the skyscraper, we can easily go up and down.
（程度高低） relative superiority or inferiority:
例：不相上下
equally matched; about the same;
难分上下
hard to tell which is better
上下的反义词
（用在数量词后面） about; or so; or thereabouts:
例：30岁上下
about thirty years old; thirty or so