1. Pertaining to functions; performed by the functions.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• functionl,
• funcitional,
• functionalit,
• functionig,
• funcional,
• functionng,
• funcitonal,
• functinoal,
• functuinal,
• functionaly,
• functiones,
• functionalty,
• functionof,
• functionial,
• fuctional,
• functionn,
• difunctional,
• functiional,
• dyfunctional,
• functionaily

• functionalism,
• fumigation,
• function,
• functionality,
• functionally,
• functioned,
• function call,
• functionalist,
• functioning,
• functions,
• function word,
• functionary.

The adjective form of the word "functional" is "functional".

The plural form of "functional" is "functionals"

The singular form of the word "functional" is "function"