A senior military commander (general or admiral); the highest-ranking officer in an army or navy.
その戦争では彼が連合軍の大将を務めた。
In that war he served as the allied forces' commander-in-chief.
大将は作戦会議で最終決定を下した。
The general made the final decision at the strategy meeting.
The head, chief, or leader of a group or organization; a boss or person in charge.
町内会の大将は近所でも頼りにされている。
The head of the neighborhood association is relied on by the locals.
あの店の大将は料理にとても厳しい人だ。
The boss of that shop is very strict about the cooking.
チームの大将として責任を感じている。
I feel responsible as the leader of the team.
A familiar or jocular way to address a man (like 'old chap' or 'boss' in casual speech).
「大将、今日は飲みに行かないか？」と先輩が声をかけた。
"Hey boss, want to grab a drink tonight?" my senior asked.
居酒屋で店主に『大将、おすすめは何ですか？』と聞いた。
At the izakaya I asked the owner, 'Boss, what's your recommendation?'
あいつはいつも友だちから『大将』と呼ばれている。
He's always called 'Taishō' by his friends.
In team competitions, the athlete who competes in the last match to decide the outcome (used in kendo, judo, etc.).
今日は大将戦で一本を取られてチームが負けた。
Today we lost the team match when the last-man bout was decided by a single point.