1. At great length.

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

• lengthly,
• lenthly,
• lenghtly,
• lengthey,
• lengthing,
• lengthie,
• kengthily,
• pengthily,
• oengthily,
• lwngthily,
• lsngthily,
• ldngthily,
• lengtily,
• lenghtily,
• lengtihly,
• lengtly,
• lenthely,
• lengthely,
• leangthly,
• Eigthily

• length,
• lengthen,
• lengthening,
• lengthwise,
• lengthiness,
• lengthy,
• lengthened,
• lengthways.

The adjective form of the word "lengthily" is "lengthy".

The plural form of "lengthily" is "lengthilies".

The singular form of the word "lengthily" is "lengthiness"