2.AdjectiveNot able to be located; gone, misplaced.
"my missing socks"
3.AdjectiveNot present when it (they) should be.
"missing data point; Joe went missing last year. He had all teeth missing when he was finally found.; We've got some flatware missing - There seem to be some cooking utensils missing too!"
4.AdjectiveOf an internal combustion engine: running roughly due to an occasional lack of a spark or other irregular fault.