Is it farther or further?
mid-15c., from Old French acreue "growth, increase, what has grown," fem. of acreu, past participle of acreistre (Modern French accroître) "to increase," from Latin accrescere (see accretion). Related: Accrued; accruing. Apparently a verb from a French noun because there is no English verb to go with it until much later, unless the record is defective.