godan verb (-ku), intransitive verb
Describes a surface that feels sticky or tacky to the touch, or something that clings unpleasantly. Often used for sweat, humidity, or adhesive substances.
暑くて肌がべたつく。
It's so hot my skin feels sticky.
このシールはべたつい
This sticker is too sticky and won't stick properly.
godan verb (-ku), intransitive verb
be close together; be stuck together
Used when things are pressed or stuck closely together, often with an unpleasant or excessive closeness. Less common than the sticky sense.
満員電車で人と人がべたつくように立っている。
On the crowded train, people are standing so close they're practically stuck together.