1extending or directly below:vast stores of gas under the North Sea the streams that ran under the melting glaciers below (something covering or protecting):under several feet of water a hot plate under an insulated lid
2at a lower level than:the room under his study behind (a physical surface):it was written on the new canvas under a gluey coating behind or hidden behind (an appearance):he had a deep sense of fun under his quiet exterior lower in grade or rank than:under him in the hierarchy
3lower than (a specified amount, rate, norm, or age):they averaged just under 2.8 per cent
4controlled, managed, or governed by:the province is now under martial law I was under his spell during the rule of:the coinage standard was reformed under Elizabeth I as a reaction to or undergoing the pressure of (something):the sofa creaked under his weight certain institutions may be under threat as provided for by the rules of; in accordance with:flowers supplied under contract by a local florist used to express grouping or classification:file it under ‘lost’ published under his own name Computing within the environment of (a particular operating system):the program runs under DOS
5undergoing (a process):under construction in a state of:children living under difficult circumstances planted with:fields under wheat
1extending or directly below something:weaving the body through the crossbars, over and under, over and under
2under water:he was floating for some time but suddenly went under affected by an anaesthetic; unconscious:the operation was quick; she was only under for 15 minutes