numeric
eleven; 11
Basic numeral meaning 11. Like other numerals, it combines with counters and time expressions, though pronunciation may adjust in some compounds.
答えは十一です。
The answer is eleven.
十一時に駅で会いましょう。
Let's meet at the station at eleven o'clock.
noun
Card-game use: 十一 can refer to the jack as the eleventh rank. In ordinary modern Japanese, ジャック is the more direct word for a jack.
このカードゲームでは、十一をジャックとして扱う。
In this card game, eleven is treated as the jack.
Transparent Sino-Japanese numeral compound: 十 means ten and 一 means one, so 十一 is literally ten-one. The card-game sense reflects treating the jack as the eleventh rank.