gāo​xià

relative superiority

高下 gāo​xià
relative superiority
relative quality or level, such as better or worse, stronger or weaker, or higher and lower; lower used for comparing skill, strength, or degree
up and down
(literary) high and low; relative height or position
relative amount
(literary) relative amount, extent, or degree of something

Frequency

Movie subtitles
1.31 per million appears in 1% of films
Written text
3.21 per million

Sources