Final answer:
The 7-letter word is Insipid, which means lacking flavor or interest and can also refer to a trite remark or a bore.
Step-by-step explanation:
The 7-letter word that can mean a trite remark, a bore, or any of the salts of hydrobromic acid is Insipid (option d).
Insipid means lacking flavor or interest, and it can be used to describe something that is dull, unexciting, or boring. It can also refer to a trite or clichéd remark. In chemistry, insipid is used to describe the salts of hydrobromic acid, which are tasteless.
An example of using insipid in a sentence is: "The speaker's presentation was so insipid that it put the entire audience to sleep."