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
verb - to make someone familiar with a new place, situation, or system, or to find your position or direction in relation to your surroundings
noun, formal - the process of familiarizing someone with a new place, situation, or system, or the ability to understand your position or direction
noun, British English, informal - an embarrassing mistake, especially one made in public
noun - a small mouse-like rodent with a rounded body, short tail, and short legs that lives mainly in fields or woodland
verb - to protect yourself or deal with a problem, attack, or unwanted situation successfully
noun - a glass container in which plants or small animals are kept and grown in controlled conditions