1. (adverb) in or to a place that is lower

• at a lower place
• beneath
• to a lower place

2. (adverb) (in writing) see below

• infra

3. (adverb) on a floor below

• down the stairs
• downstairs
• on a lower floor

4. (adverb) further down

• under

1. (adverb) in or to a place that is lower

• above
• higher up
• in a higher place
• to a higher place

2. (adverb) at a later place

• above
• supra

3. (adverb) on a floor below

• on a higher floor
• up the stairs
• upstairs