get a move on
Synonym discussion
Sense: idiom/1
All four expressions tell someone to be faster, but they differ in tone and setting. 'Get a move on' and 'hurry up' are the closest pair — both are informal spoken phrases, though 'hurry up' is more common as a bare command ('Hurry up!'). 'Get moving' shares the same casual register but emphasises starting after a pause: you might say it to someone still in bed. 'Speed up' is the most neutral of the group and works in both casual and semi-formal contexts ('We need to speed up production'). 'Step on it' comes from driving — it literally means press the accelerator harder — and is used when urging someone to go faster in a vehicle. Choose 'get a move on' when you want to sound urgent but not harsh, especially with children or friends.
Etymology
An informal British phrase that appeared in the early 20th century. It combines 'get a' — a casual way of forming an instruction in English (as in 'get a grip' or 'get a life') — with 'move on', meaning to proceed or continue forward. The expression spread widely through spoken English and is now common in many varieties of English worldwide.