D defs.my
Entry 4 senses Webster, 1913

Indentation

/ĭnˌ-dĕnˌ-tāsh'-ən/ · In·den·ta·tion · IPA /ˌɪndɛnˈteɪʃən/
01 n. The act of indenting or state of being indented.
  1. 1.
    The act of indenting or state of being indented.
  2. 2.
    A notch or recess, in the margin or border of anything; as, the indentations of a leaf, of the coast, etc.
  3. 3.
    A recess or sharp depression in any surface.
  4. 4.
    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.(Print.)
Phrases & compounds
Hanging indentation — indentation of all the lines of a paragraph except the first, which is a full line; also called a hanging indent.