adjective - working secretly, especially as a police officer trying to get information without people knowing who you really are
noun - the place where a crime happened and where the police look for clues and evidence
noun - a male reproductive cell that can join with a female egg to create a new life
noun - an animal or human in the early stages of development before birth, especially before all the main body parts are formed
noun - an organ that develops in the uterus during pregnancy to provide oxygen and nutrients to the developing baby and remove waste products from the baby's blood
adjective - not allowed or not suitable to do something or receive something, especially by law or by rules
noun - the lack of ability, skill, or knowledge needed to do something successfully or correctly
noun - the act of making two or more things happen at the same time or work together in the same rhythm, speed, or order
verb - to cause two or more things to happen at the same time or to operate together in the same rhythm or speed