Basic, centre, (most) prominent, and arch- are all synonyms for central. Side, extreme, and outer are these antonyms of central. And here are another 59 synonyms for central.
Central Synonyms
1. middle
- Centre
- Halfway
- Inner
- Innermost
- Interior
- Intermedial
- Intermediate
- Mean
- Medial
- Median
- Mesial
- Mid
- Middle
- Middling
- Midway
- Nuclear
2. main
- (most) prominent
- Arch-
- Basic
- Capital
- Cardinal
- Chief
- Core
- Critical
- Crucial
- Dominant
- Essential
- First
- Focal
- Foremost
- Fundamental
- Highest
- Key
- Leading
- Main
- Major
- Master
- Most important
- Overriding
- Paramount
- Pivotal
- Pre-eminent
- Predominant
- Premier
- Primary
- Prime
- Principal
- Ruling
- Salient
- Staple
- Supreme
- Top
- Topmost
- Ultimate
- Uppermost
- Utmost
- Vital
- Number-one