Generally; usually. An adverb indicating that something is true in most cases.
会議は大概午後2時に始まる。
The meeting generally starts at 2 p.m.
彼の言うことは大概正しいが、時々例外がある。
What he says is usually correct, but there are occasional exceptions.
大概それで問題ないでしょう。
That will probably be fine.
Nearly all; most. Used as a noun or adverb to indicate that something applies to almost everything or most cases.
学生は大概宿題を終えていた。
Most of the students had finished their homework.
この町の店は大概夜9時に閉まる。
Most shops in this town close at 9 p.m.
The gist; the summary or outline. A noun meaning the main points of something.
会議の大概をメモしておいてください。
Please take notes of the main points of the meeting.
話の大概は理解したが、細部はまだ不明だ。
I understood the gist of the story, but the details are still unclear.
Moderation; not going too far—used in expressions like 'to keep within reasonable bounds'.
飲み過ぎないように大概にしておきなさい。
Don't drink too much; keep it moderate.
大概にしておけば、後で後悔することは少ない。
If you keep things moderate, you're less likely to regret them later.
Probably; perhaps. An adverb expressing that something is likely to be the case.
彼は大概来ないだろう。
He probably won't come.
大概明日は雨が降るだろうと言われている。
They say it will probably rain tomorrow.
Considerably; greatly. An adverb indicating a large degree or extent.
彼の成績は大概向上した。
His grades have improved considerably.
この仕事は大概手間がかかる。
This job takes quite a bit of effort.