This is the 1593rd most frequent Russian word.
страшно
"Strashno" means "scary" or "terrifying"; it can also mean "very" or "extremely" in colloquial contexts.
Here, 'страшно' signifies a feeling of fear or apprehension.
Мне страшно идти туда ночью.
I am afraid to go there at night.
In this context, 'страшно' functions as an intensifier, emphasizing the degree of interest.
Он рассказывал страшно интересную историю.
He was telling a fascinatingly interesting story.
Here, 'страшно' describes something that causes fear or unease.