a team that plays football
"The rugby club sent their eleven onto the field to face the opposing team."
A cricket team of eleven players. Hence first eleven - the team of best cricket players (at a school), second eleven - the "B" team, etc.
"The young captain was thrilled to be named to the school's first eleven for the upcoming county match."
In plain English: Eleven is the number that comes right after ten and before twelve when you count up to it.
"The clock struck eleven when we arrived at the station."
Usage: In cricket contexts, use "first eleven" to refer to the senior squad and "second eleven" for reserve teams rather than using ordinal numbers like "the 1st team." This specific usage distinguishes competitive levels within a school or club without needing to specify player counts.
The cardinal number occurring after ten and before twelve. Represented as 11 in Arabic digits.
"There are eleven apples on the table, which is represented by the digit 11."
The word eleven comes from Old English endleofan, which literally meant "one left" after counting to ten. This original sense of having one remaining traces back to a Proto-Indo-European root meaning "to leave or remain."