1. That may be altered.

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

• vulterable,
• zlterable,
• slterable,
• wlterable,
• qlterable,
• alteerable,
• aletrable,
• allterable,
• altarable,
• utterrable,
• utterabel,
• udterable,
• alterablenes,
• Moterable,
• Altertble,
• Alteretable,
• beteraile,
• apteralll,
• Alterabyly,
• Alterabely

• alliterate,
• altered,
• alliterative,
• altercate,
• alteration,
• alliterator,
• altieri,
• altier,
• Alteri,
• aliterate,
• alterability,
• alternator,
• alterative,
• alter ego,
• alternate,
• alatorre,
• alternately,
• aletris.

The adjective form of the word "alterable" is "alterable".

The plural form of the word "alterable" is "alterables".

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