1. An archaic or obsolete expression.

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

• mechaism,
• sarchasm,
• anchisa,
• archais,
• archeise,
• zrchaism,
• srchaism,
• wrchaism,
• archaizm,
• archaisem,
• arcaism,
• arkhaism,
• archeism,
• archaysm,
• archrfish,
• arghasid,
• archeresse,
• manichaism,
• yahweism,
• archosom

• archaicism,
• archaic,
• archaistic,
• arachis,
• archaize,
• archaise.

The adjective form of the word "archaism" is "archaic".

The plural of the "archaism" can be the "archaisms".

The singular of the "archaism" can be the "archaism".