Abarim Publications' online Biblical Hebrew Dictionary
The verb קדר (qadar) means to be or become dark, whether of appearance or of mood (Micah 3:6, Jeremiah 4:28).
There are a few verbs that either mean darkness or have to do with it, and there are also quite a few bearing a meaning of glumness. Our verb קדר (qadar) essentially seems to denote a dishevelment; a person would have his clothes dirty and in disarray, and this typically either caused by a state of grief or designed to demonstrate it (Jeremiah 8:21). Heavenly bodies would lose their shine, go dim or dark all together (Jeremiah 4:28, Joel 2:10). Job mentions a brook to be in this state (turbid) because of ice (Job 6:16).
HAW insists that "darkness denotes the whole range of what is harmful or evil," but this is simplifying a complex matter into a fallacy. Some of the greatest events in Scripture are accompanied by darkness: the creation (Genesis 1:2), the Abrahamic covenant (Genesis 14:12), even the crucifixion (Matthew 27:45). The Bible isn't a simple bi-polar story of good and bad, but displays a highly dynamic but mono-polar system of evolution. All things come from God (Isaiah 45:7), and all things work for good to those who love God (Romans 8:28).
And that makes Song 4:7 all the more beautiful (while it should probably also be stressed that the bride is not sad that she is black, but rather ashamed of the fact that she has to slave in the field, and that she is not as pretty as she might have been if the sun hadn't burned her skin).
This verb is often used in connection with the end times, when the sun will grow dark and people will mourn (Isaiah 13:10, Zephaniah 1:15).
Derivatives of this verb are
- The feminine noun קדרות (qadrut), meaning darkness. This noun is used only in Isaiah 50:3.
- The adverb קדר (qedorannit), meaning mourners. This word is used only in Malachi 3:14.