1590s, contraction of Middle English prepositional phrase ine stede (early 13c.; see stead), itself a loan-translation of Latin in loco (French en lieu de). Typically written as two words until mid-17c.
Felix became a herpetologist instead
used English terms instead of Latin ones
instantiate
instantly
instate
instatement
instauration
instead
instellation
instep
instigate
instigation
instigator