In this repaired English vocabulary question, select the word which is closest in meaning to the definition "a standard or principle by which something is judged or decided".

Introduction / Context:
The original question text only said "Select the synonym of" and was incomplete. Applying the recovery first policy, we repair the stem to test a clear and meaningful concept. Now the question asks you to select the word that best matches the definition "a standard or principle by which something is judged or decided". This type of vocabulary question is very common in English sections of competitive exams and tests your understanding of exact word meanings.

Given Data / Assumptions:

• The repaired definition is "a standard or principle by which something is judged or decided".
• The options are "Fortuitous", "Contingent", "Criterion", "Arbitrary", and "Digression".
• Only one of these words correctly fits the given definition.

Concept / Approach:
The key is to match the definition with the precise dictionary meaning of each option. "Criterion" is the standard word for a rule or principle used to judge or evaluate something, for example admission criteria or selection criteria. The other words belong to different idea groups: chance, dependence, randomness, and wandering from the topic. Understanding such subtle differences is essential for scoring well in vocabulary questions.

Step-by-Step Solution:
Step 1: Focus on the main idea: a standard or principle used for judgment or decision making. Step 2: Consider "criterion". It means a principle or standard by which something may be judged or decided. This exactly matches the definition. Step 3: Consider "fortuitous". It means happening by chance or accident, not a standard of judgment. Step 4: Consider "contingent". It means dependent on certain conditions or circumstances, again not a judging standard. Step 5: Consider "arbitrary". It means based on random choice or personal whim rather than a fixed standard, almost the opposite of a clear criterion. Step 6: Consider "digression". It means a temporary departure from the main subject in speech or writing, unrelated to standards or principles. Step 7: Since only "criterion" fits, it must be the correct answer.

Verification / Alternative check:
You can verify by recalling common usage such as "The main criterion for selection is merit" or "Several criteria are used to rank the candidates". In all such contexts, "criterion" or its plural "criteria" clearly refers to a standard or principle for judgment. None of the other words can be substituted into these sentences without making them meaningless or incorrect.

Why Other Options Are Wrong:
"Fortuitous" deals with luck and chance events, not standards. "Contingent" describes dependence on conditions, not a measuring rule. "Arbitrary" is about decisions made without standards, the opposite idea. "Digression" refers to moving away from the main topic in writing or speech. Since the question is about a standard or principle, these options clearly do not fit.

Common Pitfalls:
Students often confuse advanced vocabulary words when they see them out of context. Some may pick "arbitrary" simply because it appears in formal English, without checking its meaning. Others may not recognise that "criterion" is the singular form and "criteria" is the plural, leading to uncertainty. To avoid such errors, regularly revise important academic words and learn them with clear example sentences and collocations.

Final Answer:
The correct synonym for the given definition is Criterion.