Nuance Dictionary / Anxiety & Uncertainty
아슬아슬하다 a-seul-a-seul-ha-da
Risky, on the edge, or narrowly avoiding disaster
The visual of someone walking on a tightrope. If a glass cup is teetering on the absolute edge of a table, it looks '아슬아슬하다'. If you arrive at the airport 2 minutes before the gate closes, your timing was '아슬아슬하다'.