Sydney Sweeney Drops Sexy Video Promoting New Lingerie Line SYRN

Sydney Sweeney just announced the launch of her new lingerie line ... and now we have a crazy hot video giving a much more enticing look at what she has in store.

In an Instagram video shared Tuesday, Sydney flaunts her sexy figure in every angle and mood.

The caption for the video reads, "Our four SYRNs: Seductress, Romantic, Playful and Comfy."

As you know ... Sydney snuck up an L.A. mountain a few days ago, climbed the iconic HOLLYWOOD Sign, and decorated it with bras ... all to promote her new business venture.

We're told the little stunt could land her in deep water, and The Hollywood Chamber of Commerce is still investigating. Something tells us things will turn out OK for the 28-year-old actress. Jeff Bezos is one of her company's investors and ... he can surely afford to pay her bail.

As we reported ... the "Christy" star's new lingerie line, SYRN, is dropping tomorrow, but you can sign up now for early access at SYRN.com.