periostitis/ˌperioʹstietis/ noun

• assumed
• assumption
• assumptive
• assurance
• assure
• assured
• assurer
• Assyrian
• Assyriology
• AST
• a stab in the back
• astable
• astatic
• astatine
• aster
• -aster
• asterisk
• asterism
• astern
• asteroid
• as the crow flies
• asthenia
• asthenosphere
• as thick as a plank/two short planks
• as thick as thieves