empirical (adj.) Look up empirical at Dictionary.com
1560s, originally in medicine, "pertaining to or derived from experience or experiments," from Latin empiricus (n.) "a physician guided by experience," from Greek empeirikos "experienced," from empeiria "experience; mere experience or practice without knowledge," especially in medicine, from empeiros "experienced (in a thing), proven by use," from assimilated form of en "in" (see en- (2)) + peira "trial, experiment," from PIE *per-ya-, suffixed form of root *per- (3) "to try, risk." With -al (1). In a general sense of "guided by mere experience" from 1757. Related: Empirically (1640s as "by means of observation and experiment").