As a Noun: 1. The lowest part of something; the lowest layer or thing in a series; the least powerful or important level in an organisation; the worst student in a class. English = bottom. 2. The ground at the bottom of the sea or a river. English = sea bed, river bed. As a Verb or Adjective: 1. To be or be located at the lowest part of something; to be the lowest layer or thing in a series; to have the least powerful or least important level in an organisation; to be the worst student in a class. English = (be) bottom. 2. To be located on the ground at the bottom of the sea or a river.