デコレーションdekoreeshon

1. noundecoration

• Synonym飾りかざりNeutral「飾り」 is the everyday word for a decoration or ornament; 「デコレーション」 is heard mostly for cakes and festive decorations such as Christmas.
• Synonym装飾そうしょくWritten「装飾」 is written, formal prose for ornamentation, as in 「室内装飾」; 「デコレーション」 is a loanword used mainly for cakes and holiday decorations.
• Synonym飾り物かざりものNeutral「飾り物」 is a decorative object or display piece, like New Year ornaments, and figuratively a leader in name only; 「デコレーション」 stresses the overall effect.
• Synonym飾り付けかざりつけNeutral「飾り付け」 is decorating or setting up a place, such as a venue or a Christmas tree; it swaps freely with 「デコレーション」 and sounds more everyday.
• SynonymオーナメントNeutral「オーナメント」 is a loanword for individual ornaments such as Christmas tree baubles; 「デコレーション」 refers to the decoration as a whole.
• Synonym装飾品そうしょくひんWritten「装飾品」 is a formal word for items used in decoration; 「デコレーション」 covers both the act and the objects and is more colloquial.
• Synonym装飾物そうしょくぶつWritten「装飾物」 is a written word for decorative objects, seen mostly in explanatory text; 「デコレーション」 is more common and also names the act of decorating.
• Related修飾しゅうしょくWritten「修飾」 means embellishing the appearance, and in grammar, modification; 「デコレーション」 is about decorating physical things.
• Related据え物すえものWritten「据え物」 is an old-fashioned word for ornaments placed in a room, with unrelated other senses; very rare — say 「飾り」 or 「置物」 instead.

For cakes and festive decorations use 「デコレーション」, as in 「デコレーションケーキ」. For everyday decoration say 「飾り」, for formal interior work 「装飾」, and for setting up a venue 「飾り付け」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 飾り付かざりつけること。装飾そうしょく。飾かざり。