cruci-, crux

(Latin: cross, crosslike; from the gallows tree)

across
1. On, at, or from the other side of; a grammatical word indicating that someone or something is on the opposite side of something or moves or reaches from one side to the other: "They ran across the street".
2. So as to cross; through: "The little girl drew lines across the paper".
3. From one side of to the other: "We drove our car on the bridge that would take us across a river".
4. Into contact with: "Mandy came across her old roommate".
5. From one side to the other: "The footbridge swayed when we ran across it.
6. On or to the opposite side: "We came across the bay by ferry".
7. Crosswise; crossed.
8. In such a manner as to be comprehensible, acceptable, or successful: "Our parents put our idea across to the rest of the family".
9. Being in a crossed position: "Her mother was seated with her arms across her chest".
cross
1. A structure consisting essentially of an upright and a transverse piece, upon which people were formerly put to death.
2. Any object, figure, or mark resembling a cross, as two intersecting lines.
3. A mark resembling a cross, usually an X, made instead of a signature by a person who is unable to write out words.
4. The Cross, when capitalized refers to the cross upon which Jesus Christ was crucified.
5. A figure of the Cross (a crucifix) as a Christian emblem, or as a symbol of Christianity; a badge, etc.
6. A sign made with the right hand by tracing the figure of a cross in the air or by touching the fore heard, chest, and shoulders, as an act of devotion usually by Roman Catholics.
7. A structure or monument in the form of a cross, set up for prayer, as a memorial, etc.
8. Any of various conventional representations or modifications of the Christian emblem used symbolically or for ornament, as in heraldry or art; such as, a Latin cross; a Maltese cross.
9. A crossing of animals or plants; a mixing of breeds.
10. An animal, plant, breed, etc., produced by crossing; that is, crossbreeding.
12. A place for crossing.
13. To bear one's cross; that is, to accept trials or troubles (tribulations) patiently.
14. Being in an ill humor; grouchy, bad-tempered, petulant, testy, cranky, disagreeable.
15. Being antagonistic or contrary; contrary, opposite, antagonistic, adverse: such as, they are working at cross purposes.
cross, cross
cross (KRAHS)
1. An upright post with a transverse piece near the top, on which condemned persons were executed in ancient times: "In ancient history, thieves were often hung on a cross to die a slow death."
2. A mark or pattern formed by the intersection of two lines, especially such a mark (X) used as a signature: "Because she never went to school, she had not learned to write, so her signature was a careful cross on the paper."
cross (KRAHS)
Showing anger or ill humor; being annoyed: "After the vase had been broken, the little girl cried to her mother, 'Please, don't be cross at me, I am sorry'."

Please don’t be cross with me. I injured my hand and I can only make a cross on the paper instead of my usual signature.

crossed electrophoresis
A technique for electrophoretic separation (science of objects moving in a fluid when an electric charge is applied) of mixed proteins in which two successive currents are passed through the support medium in directions at right angles to each other.

It is used in two-dimensional immunoelectrophoresis, separation and identification of proteins based on differences in electrical charge and reactivity with antibodies.

crossed eye
A deviation of the visual axis of one eye toward that of the other eye; or strabismus, a condition in which the visual axes of the eyes are not parallel and the eyes appear to be looking in different directions.
crossed hemianopia, heteronymous hemianopia
Either bitemporal or binasal hemianopsia (blindness in one-half of the visual field).
cross-pollination
1. The transfer of pollen from the flower of one plant to the flower of a plant having a different genetic constitution.
2. A sharing or interchange of knowledge, ideas, etc., as for mutual enrichment; cross-fertilization.
crucial
1. Extremely significant or important; such as, a crucial problem.
2. Vital to the resolution of a crisis; decisive; as a crucial election.
3. Having the form of a cross; cross-shaped.

A crucial election is like a signpost because it shows which way the electorate is moving. The metaphor of a signpost, in fact, gives us the sense of the word crucial, "of supreme importance, critical."

Francis Bacon used the phrase instantia crucis, "crucial instance," to refer to something in an experiment that proves one of two hypotheses and disproves the other.

Bacon's phrase was based on a sense of the Latin word crux, "cross", which had come to mean "a guidepost that gives directions at a place where one road becomes two", and hence was suitable for Bacon's metaphor.

Both Robert Boyle, often called the father of modern chemistry, and Isaac Newton used the similar Latin phrase experimentum crucis, "crucial experiment".

When these phrases were translated into English, they became "crucial instance" and "crucial experiment".

crucially
Extremely important because many other things depend on it; as with, The orchestra wants to win over fans and, more crucially, radio producers.
cruciate, cruciately
1. Arranged in or forming a cross; cruciform.
2. Overlapping or crossing, as the wings of some insects when at rest.
3. Shaped like a cross: the cruciate ligaments of the knee.
crucible
1. A heat-resistant container in which ores or metals are melted.
2. The hollow part at the bottom of a furnace where molten metal collects.
3. A place or set of circumstances where people or things are subjected to forces that test them and often make them change.
4. A severe test, as of patience or belief; a trial.
5. A severe trial or ordeal.
6. A place, time, or situation characterized by the confluence of powerful intellectual, social, economic, or political forces.
crucifer
cruciferous
1. One who bears a cross in a religious procession.
2. Any of various plants in the mustard family (Cruciferae or Brassicaceae), which includes the alyssum, candytuft, cabbage, radish, broccoli, and many weeds.
crucified
1. Having killed someone who has been tied to or nailed to a cross and left there to die.
2. Someone who was severely punished or damaged; such as, "She crucified me when she found out what I did to her birthday cake!"
crucifier
1. One who crucifies.
2. Someone who subjects himself/herself or another to a painful trial.