turn (v.)

late Old English turnian "to rotate, revolve," in part also from Old French torner "to turn away or around; draw aside, cause to turn; change, transform; turn on a lathe" (Modern French tourner), both from Latin tornare "to polish, round off, fashion, turn on a lathe," from tornus "lathe," from Greek tornos "lathe, tool for drawing circles," from PIE root *tere- (1) "to rub, turn." Transitive sense in English is from c. 1300. Related: Turned; turning.

Use in expression to turn (something) into (something else) probably retains the classical sense of "to shape on a lathe." To turn up "arrive, make an appearance" is recorded from 1755. Turn about "by turns, alternately" is recorded from 1640s. To turn (something) loose "set free" is recorded from 1590s. Turn down (v.) "reject" first recorded 1891, American English. Turn in "go to bed" is attested from 1690s, originally nautical. To turn the stomach "nauseate" is recorded from 1620s. To turn up one's nose as an expression of contempt is attested from 1779.

Turning point is attested by 1640s in a figurative sense "point at which a decisive change takes place;" literal sense "point on which a thing turns; point at which motion in one direction ceases and that in another or contrary direction begins" is from 1660s.

turn (n.)

c. 1200, "action of rotating," from Anglo-French tourn (Old French torn, tour), from Latin tornus "turning lathe;" also partly from turn (v.). Meaning "an act of turning, a single revolution or part of a revolution" is attested from late 15c. Sense of "place of bending" (in a road, river, etc.) is recorded from early 15c. Meaning "beginning of a period of time" is attested from 1853 (as in turn-of-the-century, from 1921 as an adjectival phrase).

Sense of "act of good will" is recorded from c. 1300. Meaning "spell of work" is from late 14c.; that of "an individual's time for action, when these go around in succession" is recorded from late 14c. The automatic automobile turn-signal is from 1915. Turn-sick "dizzy," is attested from early 15c. Phrase done to a turn (1780) suggests meat roasted on a spit. The turn of the screw (1796) is the additional twist to tighten its hold, sometimes with reference to torture by thumbscrews.

Definitions of turn
turn (v.)
change orientation or direction, also in the abstract sense;
She turned from herself and learned to listen to others' needs
The mugger turned and fled before I could see his face
turn (v.)
undergo a transformation or a change of position or action;
We turned from Socialism to Capitalism
The people turned against the President when he stole the election
Synonyms: change state
turn (v.)
undergo a change or development;
He turned traitor
The water turned into ice
Synonyms: become
turn (v.)
cause to move around or rotate;
turn your palm this way
turn a key
turn (v.)
change to the contrary;
the tides turned against him
public opinion turned when it was revealed that the president had an affair with a White House intern
Synonyms: change by reversal / reverse
turn (v.)
pass to the other side of;
turn the corner
Synonyms: move around
turn (v.)
pass into a condition gradually, take on a specific property or attribute; become;
The weather turned nasty
Synonyms: grow
turn (v.)
let (something) fall or spill from a container;
turn the flour onto a plate
Synonyms: release
turn (v.)
move around an axis or a center;
The wheels are turning
turn (v.)
cause to move around a center so as to show another side of;
turn a page of a book
Synonyms: turn over
turn (v.)
to send or let go;
They turned away the crowd at the gate of the governor's mansion
turn (v.)
to break and turn over earth especially with a plow;
turn the earth in the Spring
Synonyms: plow / plough
turn (v.)
shape by rotating on a lathe or cutting device or a wheel;
turn the legs of the table
turn the clay on the wheel
turn (v.)
change color;
In Vermont, the leaves turn early
turn (v.)
twist suddenly so as to sprain;
I turned my ankle and couldn't walk for several days
Synonyms: twist / sprain / wrench / wrick / rick
turn (v.)
cause to change or turn into something different; assume new characteristics;
The princess turned the frog into a prince by kissing him
The alchemists tried to turn lead into gold
turn (v.)
accomplish by rotating;
turn a somersault
turn cartwheels
turn (v.)
get by buying and selling;
the company turned a good profit after a year
turn (v.)
cause to move along an axis or into a new direction;
turn your face to the wall
turn the car around
turn your dance partner around
turn (v.)
channel one's attention, interest, thought, or attention toward or away from something;
people turn to mysticism at the turn of a millennium
The pedophile turned to boys for satisfaction
turn (v.)
cause (a plastic object) to assume a crooked or angular form;
the strong man could turn an iron bar
Synonyms: flex / bend / deform / twist
turn (v.)
alter the functioning or setting of;
turn the heat down
turn the dial to 10
turn (v.)
direct at someone;
They turned their flashlights on the car
She turned a smile on me
turn (v.)
have recourse to or make an appeal or request for help or information to;
She turned to her relatives for help
Synonyms: call on
turn (v.)
go sour or spoil;
The cream has turned--we have to throw it out
Synonyms: sour / ferment / work
turn (v.)
become officially one year older;
She is turning 50 this year
turn (n.)
a circular segment of a curve;
Synonyms: bend / crook / twist
turn (n.)
the act of changing or reversing the direction of the course;
he took a turn to the right
Synonyms: turning
turn (n.)
(game) the activity of doing something in an agreed succession;
it is my turn
Synonyms: play
turn (n.)
an unforeseen development;
events suddenly took an awkward turn
Synonyms: turn of events / twist
turn (n.)
a movement in a new direction;
the turning of the wind
Synonyms: turning
turn (n.)
the act of turning away or in the opposite direction;
he made an abrupt turn away from her
turn (n.)
turning or twisting around (in place);
Synonyms: twist
turn (n.)
a time period for working (after which you will be relieved by someone else);
Synonyms: go / spell / tour
turn (n.)
(sports) a division during which one team is on the offensive;
Synonyms: bout / round
turn (n.)
a short performance that is part of a longer program;
Synonyms: act / routine / number / bit
turn (n.)
a favor for someone;
he did me a good turn
Synonyms: good turn
turn (n.)
taking a short walk out and back;
we took a turn in the park