particularly; especially; in particular
Used to single out something from a group or to emphasize a specific point. Often appears at the beginning of a sentence or before the emphasized word.
It's especially hot today.
Is there anything in particular you want?
Among Japanese food, I especially like sushi.
I don't have any particular plans today.
It's especially hot today.
特に is a general-purpose 'especially', while ひときわ specifically emphasizes visual or sensory conspicuousness among similar things.