lift·off 
/ˈlɪftˌɑ:f/ noun
plural lift·offs /ˈlɪftˌɑ:f/ noun : the upward movement from the ground by a rocket, helicopter, or space vehicle as it begins flight [noncount] ▪ moments after liftoff ▪ We have liftoff! [count] ▪ a series of successful liftoffs ▪ Thousand of spectators gathered to watch the liftoff of the space shuttle. — see also lift off at 1lift
