English
sillyism
From silly + -ism.
Formed from silly + -ism
Proto-Germanic *sēliz ‘happy’
Proto-West Germanic *sāli ‘happiness’
Proto-West Germanic *sālīg ‘blissful’
Old English sǣliġ ‘lucky’
Middle English seely
English silly
Today it means
noun silliness
Language periods are conventional ranges, not dates for this word.
Etymograph / sillyism