1. (adjective) four times as great or many

• four-fold
• quadruple

2. (adjective) having four units or components

• four-fold
• quadruple
• quadruplex
• quadruplicate

3. (adverb) by a factor of four

• four times

1. (adjective) four times as great or many

• multiple

2. (adjective) having four units or components

• multiple

1. (adverb) by a factor of four

• four-fold
• quadruple