From Longman Dictionary of Contemporary Englishtailwindtail‧wind /ˈteɪlˌwɪnd/ noun [countable] HEMTTa wind blowing in the same direction that something or someone is travelling → headwind
Examples from the Corpus
tailwind• The twenty-knot tailwind helped, and their airspeed of two hundred knots reduced the journey to just over four hours. 