You tell specifically what the word means
When one wishes to know the eytomology/historical/orrt origins of a word.
Neither. It is the bare infinitive form of the verb. It can be singular or plural when used with a subject, and spelled accordingly.
"analyse", "break down", "canvas", "canvass", "dissect", "examine", "psychoanalyse", "psychoanalyze", "study" and "take apart"
analysis