1. Not explained.

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

• unscaved,
• onvolved,
• insolted,
• obsolved,
• unsovled,
• incolved,
• inolved,
• univolved,
• unsolve,
• unsloved,
• ensalved,
• uresolved,
• inwolved,
• unersolved,
• infolved,
• unsilled,
• unreolved,
• ansolved,
• unvolved,
• unbelved

• unsoiled,
• unsolder,
• uncool,
• uncoil,
• uncolored,
• unsolicited,
• unsold,
• unusual,
• uncollected,
• unsoluble,
• unsolvable,
• uncoiled,
• unsoldierly.

The adjective form of the word "unsolved" is "unsolvable".

The plural form of the word "unsolved" is "unsolved". The word does not change in plural form as it is an adjective that describes a noun.

The singular form of the word "unsolved" is "unsolved". The word does not change in its singular form.