A secret that is classed as "top secret"; a top-secret secret; top-secret information. / Used other than figuratively or idiomatically: see top, secret.

a stream formed by the confluence of two first order streams, or of a first order stream and a second order stream

A cutting; a part cut out from the rest of something. / A part, piece, subdivision of anything. / (music) A group of instruments in an orchestra. / A part of a document. / An act or instance of cutting.

To cut, divide or separate into pieces. / To reduce to the degree of thinness required for study with the microscope.

A grandchild of a grandparent's sibling. / A relative who has with the other person only two great-grandparents in common, but where the parents and grandparents are different.

A child of a second cousin. / A second cousin of a parent.

A violinist who is assigned to play the second violin part.

The second violin part in an orchestral score, generally a harmony to the first violin's melody and generally less technically demanding.

(music) A fiddle part in harmony to the first fiddle. / (music) The person playing second fiddle. / (idiomatic) A sidekick or subordinate, or the role of such a person.

(geometry) A straight line that intersects a curve at two or more points. / (trigonometry) In a right triangle, the reciprocal of the cosine of an angle. Symbol: sec