enter outside of itself, so as to return periodically to the same
relative position that it held at some previous time. A _revolving_ body
may also either _rotate_ or _roll_ at the same time; the earth
_revolves_ around the sun, and _rotates_ on its own axis; in popular
usage, the earth is often said to _revolve_ about its own axis, or to
have a daily "revolution," but _rotate_ and "rotation" are the more
accurate terms. A cylinder over which an endless belt is drawn is said
to _roll_ as regards the belt, tho it _rotates_ as regards its own axis.
Any object that is in contact with or connected with a _rolling_ body is
often said to _roll_; as, the car _rolls_ smoothly along the track.
Objects whose motion approximates or suggests a rotary motion along a
supporting surface are also said to _roll_; as, ocean waves _roll_ in
upon the shore, or the ship _rolls_ in the trough of the sea. _Turn_ is
a conversational and popular word often used vaguely for _rotate_ or
_revolve_, or for any motion about a fixed point, especially for a
motion less than a complete "rotation" or "revolution;" a man _turns_
his head or _turns_ on his heel; the gate _turns_ on its hinges.

Antonyms:

bind, chafe, grind, slide, slip, stand, stick.

* * * * *

RIDDLE, _n._

Synonyms:

conundrum, enigma, paradox, problem, puzzle.

_Conundrum_, a word of unknown origin, signifies some question or
statement in which some hidden and fanciful resemblance is involved, the
answer often depending upon a pun; an _enigma_ is a dark saying; a
_paradox_ is a true statement that at first appears absurd or
contradictory; a _problem_ is something thrown out for solution;
_puzzle_ (from _oppose_) referred originally to the intricate arguments
by which disputants opposed each other in the old philosophic schools.
The _riddle_ is an ambiguous or paradoxical statement with a hidden
meaning to be guessed by the mental acuteness of the one to whom it is
proposed; the _riddle_ is not so petty as the _conundrum_, and may
require much acuteness for its answer; a _problem_ may require simply
study and scholarship, as a _problem_ in mathematics; a _puzzle_ may be
in something other than verbal statement, as a dissected map or any
perplexing mechanical contrivance. Both _enigma_ and _puzzle_ may be
applied to any matter difficult of answer or solution, _enigma_
conveying an idea of greater dignity, _puzzle_ applying to somet