Final answer:
You would look in the dictionary entry for 'burst' to find its past tense, which is also 'burst' as it is an irregular verb that does not change form.
Step-by-step explanation:
To find the past tense of the verb 'burst' in a dictionary, you would typically look in the entry for the word 'burst' itself. Dictionaries usually provide the different forms of a verb, including the past tense, within the same entry. If 'burst' follows the pattern mentioned, the past tense would end with a '-t' or 'ed' suffix, but it is one of the few irregular verbs that does not change its form in the past tense; therefore, the past tense is also 'burst'.