Several means more than two but not very many — usually somewhere between three and about eight. Several people, several times, several weeks ago.
It is deliberately vague and that vagueness is its job: it says more than a couple and fewer than many without committing. It goes with plural countable nouns only — several chairs, never several water. Note the older and quite different legal sense, meaning separate: joint and several liability means each person is liable both together and individually, and it is a phrase worth recognising in a contract because it decides who pays.
1adjectiveseveralMore than two but not many.
“Several people said the same thing.”
synonyms: a few, some
2pronoungroupMore than two of a group.
“Several of them had already left.”
3adjectiveuseIn legal use, separate and individual.
“The partners have joint and several liability.”
Too few real examples of this word to estimate which sense is commonest.
several is a quantity.
Latin separ meant separate, and several first meant individual or belonging to each separately — which is the sense preserved in joint and several. The modern quantity sense came from talking about several persons meaning each of them, and then about how many that was.
Latin
sēpar — separate
English, today
several
From Anglo-Norman - several, from Medieval Latin - sēparālis, from Latin sēpar (“separate”). by surface analysis, sever + -al. Not related to severe or seven.
Etymology from Wiktionary, CC BY-SA