Usage, and meaning of 'imply'

In casual use, the word "implies" loosely means suggests rather than requires. However, in logic, the technical use of the word "implies" means "is a sufficient condition for".

Where there is causation, there is correlation, but also a sequence in time from cause to effect, a plausible mechanism, and sometimes common and intermediate causes. While correlation is often used when inferring causation because it is a necessary condition, it is not a sufficient condition.