as·tro·dynamics \¦as(ˌ)trōˌ\noun plural but singular or plural in construction (-s) Etymology:astr- + dynamics : celestial mechanics applied to space vehicles • as·tro·dynamic\"ˌ\adjective • as·tro·dy·nam·i·cist\¦as(ˌ)trōdīˈnaməsə̇st sometimes -də̇-\noun