noun
medicine box; first-aid kit
A box or case for storing medicines and first-aid supplies.
薬箱から絆創膏を取り出した。
I took a bandage out of the medicine box.
救急箱 specifically refers to a first-aid kit for emergencies, while 薬箱 is a more general medicine box.
Compound of 薬 (くすり, 'medicine') and 箱 (はこ, 'box'), with rendaku voicing of はこ to ばこ.