biometric (adj.)

1831, "calculation of life expectancy" (obsolete); see bio- + -metry. Coined by Whewell, popularized 1860s by T.S. Lambert. Later, "application of mathematics to the study of biology" (1894). Related: Biometer, a word used in various senses from the 1830s on; it is attested from 1865 as "life table," calculating the duration of life under given conditions.

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.