When an engine is ignited, it produces thrust and boosts the rocket into the sky. After the propellant is used up, delay is activated, producing tracking smoke and allowing the rocket a brief coast.
infirmary (plural infirmaries) 1  A place where sick or injured people are cared for, especially a small hospital; sickhouse. 2  A clinic or dispensary within another institution.
uk â /ÉªnËfÉË.mÉr.i/ us â /ÉªnËfÉË.mÉ.ri/. âº US a room in a school, college, or university where students who are injured or feeling ill can go to a nurse for treatment. âº UK old use a hospital. It is now used mainly in the names of hospitals: Leeds General Infirmary. the Royal Infirmary.