intentionally; deliberately; on purpose
Used when someone does something with conscious intent, often with a nuance of doing it unnecessarily or pointedly.
He spoke in a deliberately loud voice.
There's no need to intentionally blow the issue out of proportion.
Used to single out something as noteworthy, often in negative or contrastive contexts. Less common than the intentional sense.
Today feels especially cold.
I want to particularly emphasize this point.
特に is the standard word for 'especially' or 'particularly'. ことさら in this sense is more literary and emphatic, often used in written or formal speech.
seem contrived; appear unnatural; look forced
Usually written in kana. The kanji spelling 殊更 exists but is less common.
Kanji spelling; less common than kana. The second kanji 故 is outdated and rarely used.
Derived from こと (事, 'matter') + さら (更, 'further, again'). The combination originally meant 'on top of the matter' or 'in addition', which developed into the senses of 'intentionally' and 'especially'.