early 15c., "information, intelligence," from Middle French notice (14c.), and directly from Latin notitia "a being known, celebrity, fame, knowledge," from notus "known," past participle of (g)noscere "come to know, to get to know, get acquainted (with)," from PIE *gno-sko-, a suffixed form of PIE root *gno- "to know." Sense of "formal warning" is attested from 1590s. Meaning "a sign giving information" is from 1805.
early 15c., "to notify," from notice (n.). Sense of "to point out" is from 1620s. Meaning "to take notice of" is attested from 1757, but was long execrated in England as an Americanism (occasionally as a Scottishism, the two offenses not being clearly distinguished). Ben Franklin noted it as one of the words (along with verbal uses of progress and advocate) that seemed to him to have become popular in America while he was absent in France during the Revolution. Related: Noticed; noticing.