Noah Webster's New International Dictionary of the English Language

1. (superl.) Serious in feeling or manner; sedate; grave; austere; not light, lively, or cheerful.

2. (superl.) Very strict in judgment, discipline, or government; harsh; not mild or indulgent; rigorous; as, severe criticism; severe punishment.

3. (superl.) Rigidly methodical, or adherent to rule or principle; exactly conformed to a standard; not allowing or employing unnecessary ornament, amplification, etc.; strict; -- said of style, argument, etc.

4. (superl.) Sharp; afflictive; distressing; violent; extreme; as, severe pain, anguish, fortune; severe cold.

5. (superl.) Difficult to be endured; exact; critical; rigorous; as, a severe test.