1. Crafty; deceitful; insidious; treacherous.

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

• guiltful,
• fuileful,
• vuileful,
• buileful,
• huileful,
• yuileful,
• tuileful,
• gyileful,
• ghileful,
• gjileful,
• giileful,
• g8ileful,
• guilefull,
• gilful,
• chiceful,
• guardeful,
• moolebut,
• nooteful,
• guilefuly,
• gooffup

• guilbault,
• guilbeault,
• guilfoyle.

The adjective form of the word "guileful" is "guileful". However, "guileful" can also be spelled as "guileful," "guilefull," or "guile-filled".

The plural form of "guileful" is "guilefuls".

The singular form of the word "guileful" is "guileful".