Depending on context, PPD can mean postpartum depression or purified protein derivative, the name of the fluid injected into the skin of the arm during a screening test for tuberculosis.
Manic depression, or manic depressive disorder is nowadays more commonly known as Bipolar disorder or Bipolar affective disorder. It can also be referred to as Hypomania due to public unawareness.
Post partum depression
A pit or depression.
A waterhole is a depression in the ground that holds water. Another name for a waterhole is a lake, loch, or pond.
The Dearly Departed .
a congregation is another name for a church assembly and more commonly used
Reverend and Father are commonly used as well
An ''H bomb'' is a commonly used name.
Great Depression, Black Friday
Commonly known as columbium
Another name for the system unit is the central processing unit. This is what is commonly referred to as a processor in a computer.