part (n.)

mid-13c., "division, portion of a whole, element or constituent (of something)," from Old French part "share, portion; character; power, dominion; side, way, path," from Latin partem (nominative pars) "a part, piece, a share, a division; a party or faction; a part of the body; a fraction; a function, office," related to portio "share, portion," from PIE root *pere- (2) "to grant, allot."

It has replaced native deal (n.) in most senses. Meaning "an allotted portion, a share" is from c. 1300; that of "a share of action or influence in activity or affairs, role, duty" is by late 14c. The theatrical sense (late 15c.) is from an actor's "share" in a performance (The Latin plural partis was used in the same sense). In music, "one of the voices or instruments in a concerted piece" (1520s). Sense of "separate piece of a machine" is by 1813.

Meaning "the division of the hair on the head when dressing it; the separation of the hair on the top of the head, from which it spread down on either side" is by 1890, American English; the earlier word for this was parting (1690s). The common Middle English word for it was shede, schede, from Old English scead, scad.

As an adjective from 1590s. Late Old English part "part of speech" did not survive and the modern word is considered a separate borrowing. Phrase for the most part "most, the greatest part" is from late 14c. To take part "participate" is from late 14c.

part (v.)

c. 1200, parten "to depart, leave;" late 13c., "cause (things, persons) to separate;" from Old French partir "to divide, separate" (10c.), from Latin partire/partiri "to share, part, distribute, divide," from pars "a part, piece, a share" (from PIE root *pere- (2) "to grant, allot").

Meaning "divide" (something), especially "divide by cutting or cleaving" is from c. 1300; that of "to share something" (with others) is from early 14c. Of persons, "to separate from one another," early 14c., also intransitive, "draw or hold (persons) apart, separate by intervening." Intransitive sense of "become disunited" is from early 14c.; that of "be divided or severed" is from 1570s. Meaning "to separate the hair, comb the hair away from a dividing line" is attested from 1610s. Related: Parted; parting. To part with "surrender" is from 1580s; earlier it meant "to share with" (mid-13c.).

Definitions of part
part (n.)
something determined in relation to something that includes it;
he wanted to feel a part of something bigger than himself
Synonyms: portion / component part / component / constituent
part (n.)
something less than the whole of a human artifact;
glue the two parts together
the rear part of the house
Synonyms: portion
part (n.)
a portion of a natural object;
they analyzed the river into three parts
Synonyms: piece
part (n.)
that which concerns a person with regard to a particular role or situation;
they resisted every effort on his part
it requires vigilance on our part
part (n.)
the extended spatial location of something;
religions in all parts of the world
Synonyms: region
part (n.)
the actions and activities assigned to or required or expected of a person or group;
the government must do its part
Synonyms: function / office / role
part (n.)
an actor's portrayal of someone in a play;
she played the part of Desdemona
Synonyms: character / role / theatrical role / persona
part (n.)
assets belonging to or due to or contributed by an individual person or group;
Synonyms: share / portion / percentage
part (n.)
one of the portions into which something is regarded as divided and which together constitute a whole;
the written part of the exam
Synonyms: section / division
part (n.)
a line of scalp that can be seen when sections of hair are combed in opposite directions;
his part was right in the middle
Synonyms: parting
part (n.)
the melody carried by a particular voice or instrument in polyphonic music;
he tried to sing the tenor part
Synonyms: voice
part (n.)
the effort contributed by a person in bringing about a result;
Synonyms: contribution / share
part (n.)
an item that is an instance of some type;
my dog swallowed a Lego part
Synonyms: piece
part (v.)
go one's own way; move apart;
Synonyms: separate / split
part (v.)
discontinue an association or relation; go different ways;
Synonyms: separate / split up / split / break / break up
part (v.)
Synonyms: depart / start / start out / set forth / set off / set out / take off
part (v.)
come apart;
Synonyms: separate / divide
part (v.)
force, take, or pull apart;
Moses parted the Red Sea
Synonyms: separate / disunite / divide
part (adv.)
to some extent; in some degree; not wholly;
Synonyms: partially / partly / in part