1. size; dimension; magnitude
威力の大小は関係ない。It doesn't matter how powerful it is.
2. large and small (sizes); various sizes
大きさは大小さまざまだ。The sizes vary from large to small.
3. daishō (matched pair of long and short swords)
彼は大小を腰に差すと、厳しい表情で戻る。He thrusts his two swords into his sash and comes back with a stern look.
4. large and small drums
5. long months and short months
6. sic bo (Macao dice game); tai sai; dai siu; big and small