1. Sparingly.

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

• spearetly,
• sparkaly,
• sparcley,
• apparely,
• sparkely,
• spacaly,
• parel,
• sqaurely,
• separetly,
• sparkelly,
• sparsly,
• sqarely,
• spely,
• separtely,
• spirel,
• sparcly,
• spacealy,
• spacily,
• porely,
• sparsley

• spirilla,
• spiraling,
• spiral,
• Sperling,
• spur wheel,
• sprawl,
• spirillum,
• sprawler,
• Spruill,
• spurlin,
• sparling,
• Spurlock,
• spirally,
• sproul,
• sprawly,
• sprowl,
• sproull,
• spirula,
• Spruell,
• sporulate,
• sproule,
• sproles,
• Spurling.

The adjective form of the word "sparely" is "sparse".

The plural form of the word "sparely" is "sparelys".

The singular form of the word "sparely" is "sparely" itself. "Sparely" is an adverb and does not change in form whether used in singular or plural context.