indentation
(ɪndɛnˈteɪʃən)
[In form, n. of action f. indent v.1 (see -ation); but in sense derived also from indent v.2]
I. Senses from indent v.1
1. The action of indenting; the condition of being indented or having the edge cut into tooth-like notches or angular incisions; denticulation; toothing.
| 1836 Penny Cycl. V. 247/1 The form of leaves..margin, the manner of their indentation, and the nature of the leaf⁓stalk. 1858 Glenny Gard. Every-day Bk. 65/2 If the edge be smooth, with no indentation, and pefectly circular. 1877 F. G. Heath Fern W. 22 The indentation assuming various shapes, often being deeply incised. |
2. with an and pl. A cut, notch, or angular incision in the margin of anything; a deep recess in a coast-line, or the like; a series of incisions; a zigzag moulding, etc.
| a 1728 Woodward (J.), The margins do not terminate in a streight line, but are indented; each indentation being continued in a small ridge, to the indentation that answers it on the opposite margin. 1796 Morse Amer. Geog. II. 101 The opposite Welsh coast is broken by various bays and indentations. 1806 Med. Jrnl. XV. 69 Leaves oblong, on short leaf-stalks, blunt, wing cleft, with indentations. 1853 Kane Grinnell Exp. xxii. (1856) 170 Captain Austin..entered the same little indentation in which five of us were moored before. a 1862 Buckle Misc. Wks. (1872) I. 302 The Greek coast is full of indentations. |
3. Printing. = indention 2.
| 1864 Webster s.v., Common indentation..hanging indentation. 1884 Southward Pract. Print. 86 The first line of the paragraph..is shorter than the two following, there being a widespace at the beginning of it. This is called an indentation. |
II. Sense from indent v.2
4. The action of impressing so as to form a dent or dint; the dent, hollow, or depression thus formed; any deep and decided depression in a surface.
| 1847 James Convict ii, On the summit of one of the most elevated points..there was a little indentation. 1861 Times 11 July, Injurious compression of a soft, moist soil, by the indentation of its wheels. 1880 Bastian Brain 115 The extent of its surface is further increased by the existence of numerous superficial folds or indentations. |
5. Special Comb.: indentation hardness, hardness as determined by one of the indentation tests; indentation test, any of various tests for determining the hardness of a solid by making an indentation in a sample under standard conditions and measuring either its size or the distance travelled by the indenter.
| 1918 Proc. Inst. Mech. Engin. Oct.–Dec. 487 Researches on indentation hardness. 1956 B. W. Mott Micro-Indentation Hardness Testing i. 9 The general definition of indentation hardness..is the ratio of the load applied to the surface area of the indentation. 1968 D. A. Smith Addition Polymers x. 447 The testing of fabricated polymer components..may include evaluation of tensile stress-strain and flexural properties.., indentation hardness, and the examination of the effects of temperature on rigidity. |
| 1897 Min. Proc. Inst. Civil Engin. CXXIX. 334 (heading) A new indentation test for determining the hardness of metals. 1956 B. W. Mott Micro-Indentation Hardness Testing i. 2, (1) Static indentation test: A steady load is applied to an indenter..and the hardness is calculated from the area or depth of indentation produced. (2) Dynamic indentation test: A ball, cone or a number of small spheres is allowed to fall from a definite height and the hardness number is obtained from the dimensions of the indentation and the energy of the impact. |