A Quick and Simple Dictionary

indentation

1. Noun.  The act of indenting or state of being indented.
2. Noun.  A notch or recess, in the margin or border of anything; as, the indentations of a leaf, of the coast, etc.
3. Noun.  A recess or sharp depression in any surface.
4. Noun.  The act of beginning a line or series of lines at a little distance within the flush line of the column or page, as in the common way of beginning the first line of a paragraph.
5. Noun.  A measure of the distance from the flush line; as, an indentation of one em, or of two ems.