As a noun combination

is the act of combining, the state of being combined or the result of combining.

As a verb chorded is

(chord).

As an adjective chorded is

(computing|of a computer keyboard) through which input is supplied by pressing a relatively small number of keys in combinations, as though playing chords.

As verbs the difference between chord and chorded

is that chord is to write chords for while chorded is (chord).

As a noun chord

is (senseid)(music) a harmonic set of three or more notes that is heard as if sounding simultaneously.

As an adjective chorded is

(computing|of a computer keyboard) through which input is supplied by pressing a relatively small number of keys in combinations, as though playing chords.

As nouns the difference between eigenvector and eigenfrequency

is that eigenvector is a vector that is not rotated under a given linear transformation; a left or right eigenvector depending on context while eigenfrequency is a frequency modelled as an eigenvector.

As a noun train

is elongated portion or train can be (obsolete) treachery; deceit.

As a verb train

is to practice an ability.

As an adjective untrainable is

that cannot be trained.

As a proper noun key

is .

As a noun keyer is

one who, or that which, keys.

As nouns the difference between device and keyer

is that device is any piece of equipment made for a particular purpose, especially a mechanical or electrical one while keyer is one who, or that which, keys.

As nouns the difference between signal and keyer

is that signal is signal while keyer is one who, or that which, keys.

As nouns the difference between switch and keyer

is that switch is a device to turn electric current on]] and [[turn off|off or direct its flow while keyer is one who, or that which, keys.

As a verb switch

is to exchange.

As an adjective switch

is (snowboarding) riding with their opposite foot forward from their natural position bbc sport, [http://wwwbbccouk/sport/0/winter-olympics/26141070 "sochi 2014: a jargon-busting guide to the halfpipe"], 11 february 2014 .

As a verb code

is .

As an adjective crackable is

(of a code) that can be cracked; breakable.

As adjectives the difference between crack and crackable

is that crack is highly trained and competent while crackable is that can be cracked; breakable.

As a verb crack

is (To form cracks) To form cracks.

As a noun crack

is (thin space opened in a previously solid material)A thin and usually jagged space opened in a previously solid material.