1. Nearest in space or position; immediately adjoining without intervening space
   "our rooms were side by side"
   - adjacent, next 
2. Closely related or associated
   "a city in which communism and democracy had to live side by side"

See also: close, related, related to

• satirical
• satirically
• Protector of Boundaries
• protectoral
• protectorate
• protectorship
• Proteidae
• protein
• protein folding
• protein molecule
• proteinaceous
• proteinase
• proteinuria
• Proteles
• Proteles cristata
• proteolysis
• proteolytic
• proteolytic enzyme
• proteome
• proteomics
• proteose
• proteosome
• proteosome vaccine
• Proterochampsa
• proterozoic