偷懒 (tōu lǎn): 벙벙하다.

The boss was away on a business trip, and with no one supervising the office, Xiao Wang goofed off and played on his phone all afternoon.

I only scored 60 on this exam because I kept slacking off while reviewing and didn't go over many key points.

Mom asked me to clean the house, but I hid in my room goofing off. She caught me and gave me a scolding.

With the coach standing there watching, none of the players dared to slack off, and they did every move very seriously.

He is extremely diligent at work and never slacks off, so his name is on this promotion list.