1704 C. Hayes Treat. Fluxions iii. 20 Thus the Sub-normals of all sorts of Paraboliform Figures may be Investigated.

1762 J. Rowe Introd. Doctr. Fluxions (ed. 2) vi. 110 When the Subnormal is equal to the vertical Distance, or y = 0, the said vertical Distance will be Nothing.

1842 G. W. Francis Dict. Arts (at cited word) In all curves the subnormal is the third proportional to the subtangent and the ordinate.

1885 T. H. Eagles Constructive Geom. Plane Curves 62 The focus F is found by drawing the normal at any point D, bisecting the sub-normal NG and setting off AF = ½ NG.

1935 A. H. G. Palmer & K. S. Snell Mechanics ii. 21 Prove that the sub-normal of a velocity-distance graph gives the acceleration.

1986 C. K. Austin Site Carpentry (rev. ed.) iv. 39/2 The distance ‘Sn’ (subnormal) becomes a constant value in constructing any other normals to the curve.

1905 Every Other Sunday 1 Jan. 66/2 The committee praised the teacher for her success with these sub-normals.

1920 L. S. Hollingworth Psychol. Subnormal Children viii. 146 Physical exercise will do for the mentally subnormal just what it will do for the mentally normal.

1956 J. F. Horner Summary of Scientol. 15 The children who get extra attention are the subnormals.

1975 N. O'Connor in B. H. Kirman & J. Bicknell Mental Handicap iv. 102 The generally slowed reaction time to both visual and auditory, simple and complex stimulus-response situations which characterizes all subnormals.

2009 Age (Melbourne) (Nexis) 4 June 44 The new Bill and Ben..appear to be inbred subnormals who enjoy each other's company for reasons quite apart from unintelligible conversation.

1843 E. Newman Syst. Nature (ed. 2) i. 12 It now becomes necessary to examine the remaining groups of placental animals, and if we consider Primates to be the normal group, I think we shall find it convenient to divide the remainder into three subnormal and three abnormal groups.

1847 W. S. Chipley & R. P. Hunt tr. F. Andry Man. Diagnosis Dis. Heart 101 I divide into six principal categories, the diverse sounds perceived by our ear when we auscult a heart. These sounds are normal, super-normal, sub-normal, modified, replaced, or accompanied.

1897 Month Sept. 329 All subnormal or supernormal phenomena of the soul.

1897 T. C. Allbutt et al. Syst. Med. III. 728 The temperature [in colic] is usually rather subnormal.

1936 N. Feather Introd. Nucl. Physics ix. 149 Hard γ rays are chiefly emitted from those atoms which have just previously ejected an electron of sub-normal energy.

1974 V. B. Mountcastle et al. Med. Physiol. (ed. 13) II. lx. 1416/2 Acidosis is an abnormal condition caused by the presence in the body of excessive amounts of acid or by reduction of the amount of alkali to a subnormal level.

2007 Independent 20 Feb. (Extra section) 12/3 The optician refused to be drawn on why my peripheral vision was subnormal.

1898 F. Warner Study of Children (new ed.) p. vii I was enabled to examine individually 100,000 children upon a fixed plan, taking a written description on a schedule for each child in any one point subnormal, or reported by the teacher as dull or backward.

1919 H. Woodrow Brightness & Dullness in Children ii. 22 In 1904, the French Minister of Public Instruction made him [sc. Binet] a member of a commission appointed for the purpose of organizing classes for subnormal children.

1935 C. L. Burt Subnormal Mind ii. 77 In another 12 per cent. the parent, though not intellectually subnormal, was more or less unstable.

1940 A. O. Heck Educ. Exceptional Children xxiii. 342 Frequently, children are referred to as bright, average and subnormal.

1967 Punch 19 Apr. 557/1 Down below the plimsoll line of an IQ of fifty are the erstwhile imbeciles and idiots, now classed as SSN—severely subnormal.

1989 P. D. James Devices & Desires xiv. 93 Alex turned to her and spoke each word loudly and clearly as if she were a subnormal child.

2008 E. Herman Kinship by Design v. 171 Figuring normal children as adoptable and subnormal children as unadoptable was a staple of the era's eugenic ideology.