1. (adjective) having four units or components

• four-fold
• fourfold
• quadruple
• quadruplex

1. (noun) any four copies; any of four things that correspond to one another exactly

• copy

2. (verb) reproduce fourfold

• reproduce

1. (adjective) having four units or components

• multiple

1. (noun) any four copies; any of four things that correspond to one another exactly

• quadruple

2. (verb) reproduce fourfold

• quadruple