1. In a flat manner.

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

• latley,
• flauty,
• fluetly,
• latly,
• flattly,
• flirtly,
• fantly,
• flearly,
• fatley,
• featl,
• fately,
• lattly,
• flasely,
• faitly,
• firtly,
• flirly,
• flowly,
• fatle,
• flamily,
• filally

• fleetly,
• flat,
• lately,
• flatulent,
• flatlet,
• flail,
• falter,
• float,
• flailed,
• flit,
• fluently,
• fatal,
• flatley,
• flotilla.

The adjective form of the word "flatly" is "flat".

The plural form of the word "flatly" is "flatlies".

The singular form of the word "flatly" is "flat"