riddle

Concise Oxford English Dictionary © 2008 Oxford University Press:
riddle1

▶noun a question or statement phrased so as to require ingenuity in ascertaining its answer or meaning.

■ a person or thing that is difficult to understand.

▶verb archaic speak in or pose riddles.

■ explain (a riddle) to.

– derivatives
riddler noun.

– origin OE rǣdels, rǣdelse ‘opinion, conjecture, riddle’; rel. to read.

Concise Oxford English Dictionary © 2008 Oxford University Press:
riddle2

▶verb

• 1 make many holes in, especially with gunshot.

  ■ fill or permeate with something undesirable: the law is riddled with loopholes.

• 2 pass through a riddle.

  ■ remove ashes or other unwanted material from (a fire or stove) with a sieve.

▶noun a large coarse sieve, especially one for separating ashes from cinders or sand from gravel.

– origin OE hriddel, of Gmc origin.