unsaturatedadj.

1758 A. Reid tr. P. J. Macquer Elements Theory & Pract. Chym. I. 395 That portion of the Acid which remains unsaturated will dissolve the Mercury.

1791 Philos. Trans. (Royal Soc.) 81 219 Any surplus of..air would only have remained unsaturated.

1832 Nat. Philos. (Libr. Useful Knowl.) II. Electricity ii. §53 Its unsaturated matter would have exerted an attractive force on the fluid.

1866 Notices Proc. Royal Inst. Great Brit. 4 417 The two nitrogen arms which are left exposed sufficiently indicate that two attraction units remain unsaturated.

1872 London, Edinb., & Dublin Philos. Mag. 4th Ser. 43 259 A radical..is a portion of a molecule, a group of atoms, the affinities of which do not wholly saturate one another, the radical being uni-, bi-, tri-, quadri-, &c. valent, according as 1, 2, 3, 4,..affinities are left unsaturated.

1879 O. N. Rood Mod. Chromatics xviii. 307 He must mainly use the pale unsaturated colours of nature.

1916 Jrnl. Amer. Chem. Soc. 38 778 It has been generally assumed that what is known as a bivalent element must be tied by two bonds to another element or elements, or remain with an ‘unsaturated valence’.

1951 I. L. Finar Org. Chem. iv. 67 The acetylenes are unsaturated hydrocarbons that contain one triple bond.

1982 J. E. Fernandez Org. Chem. v. 89 The alkenes are unsaturated: that is they contain fewer hydrogen atoms than the alkanes.